Soft and Chewy Sourdough Monster Cookies Recipe

A little bit nostalgia, a lot of deliciousness is packed in these Soft and Chewy Sourdough Monster Cookies. Truly a monster cookie and the perfect addition to your sourdough cookie recipe collection.

A little bit nostalgia, a lot of deliciousness is packed in these Soft and Chewy Sourdough Monster Cookies. My family would make a big batch of monster cookies (not sourdough) growing up, usually in the winter. The M&Ms are SUCH a treat when you are little, not to mention how big these cookies are! Truly a monster cookie and the perfect addition to your sourdough cookie recipe collection.

I first was inspired to create this recipe after my son had asked for “cookie monsters” for his birthday dessert two years in a row! The first year I just made a non-sourdough batch that wasn’t quite what I remembered when enjoying them as a child. To me a monster cookie needs a few things:

Soft and chewy texture with crisp edges
Plenty of peanut butter flavor
Perfectly packed with oats, chocolate chips and M&M’s

I hope you love this sourdough version of a cookie that brings back so many fun memories as a child. You can either use sourdough starter or sourdough discard. I love doing a ferment on them if I have the time!

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Ingredients for Soft and Chewy Sourdough Monster Cookies

All-Purpose Flour: Unbleached is best and I like using King Arthur flour.
Baking Soda: Used to leaven the cookies.
Baking Powder: Same as baking soda. It helps leaven the cookies and help them have a good texture.
Sea Salt: Balance flavor.
Butter: Salted butter works well. You want your butter to be room temperature! Crucial for a good cookie!
Brown Sugar: I love baking with brown sugar. Good for flavor and texture.
Granulated Sugar: Just a little granulated sugar.
Eggs: This recipe uses 2 eggs. Room temperature is a good idea!
Peanut Butter: Creamy is a MUST. I talk about this more in the recipe notes.
Sourdough Starter: Here is another recipe that you can use either sourdough discard or active starter. I love long fermenting them when time allows! Have you long fermented a cookie before?
Vanilla Extract: Added for flavor….the amount is a suggestion. Measure with your heart!
Old Fashioned Oat: A monster cookie is not complete without the added oats. Love the heartiness and chewiness the oats bring.
Quick Oats: I love using a combination of old fashioned and quick oats in my recipes. I also use both for my homemade granola.
Chocolate Chips: Semi-sweet are the ones we love for this recipe, but you can choose your favorite. Dark chocolate chips would also be delicious!
M&M’s: The burst of color and fun! M&M’s bring color and fun to this recipe! I like regular milk chocolate m&m’s but you could use mini m&m candies too.
Hershey Candy Bar (Optional): If you don’t like using foods with dyes you can substitute chopped Hershey bar for the M&M’s. We loved them this way too!

Helpful Tools for Making Sourdough Monster Cookies

Kitchen Scale: Helpful to make an accurate bake.
Cooling Rack: Love having a cooling rack to keep things off the counter when cooling.
Cookie Scoop: My FAVORITE scoop. You need one.
Cookie Sheet: I love Nordic ware baking sheets. Make sure to get a lid too!

Frequently Asked Questions:

Can I use chunky peanut butter for monster cookies?

I would not. Short answer chunky peanut butter will make your cookies drier in texture. I would opt for creamy peanut butter.

Why are they called monster cookies?

This is up for debate…my thought from their unusual size and how loaded they are with delicious ingredients.

Do these cookies need to be chilled before baking them?

No! I have tested both cold and warm cookie dough and they both worked well! These cookies don’t require any chill time. If you want a thicker cookie than yes, chill the dough first. The cookies in the pictures were baked with warm dough.

More Sourdough Recipes to Try:

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Soft and Chewy Sourdough Monster Cookies Recipe

Makes 21 Cookies

1 cup (240g) butter, softened
1 cup (220g) brown sugar, packed
½ cup (100g) granulated sugar
¼ cup (50g) sourdough starter, active or discard
1 cup (250g) creamy* peanut butter
2 eggs, room temperature
2 tsp (10g) vanilla extract
1 cup (120g) all-purpose flour
1 tsp (4g) baking soda
1 tsp (4g) baking powder
½ tsp (3g) sea salt
1 cup (90g) old-fashioned oats
1 cup (90g) quick oats
3 cups inclusions, a combination of M&M’s and Chocolate Chips*

Instructions for Soft and Chewy Sourdough Monster Cookies

Preheat your oven to 325 degrees. (Skip this step if you are planning to make these cookies long fermented.)
In a large bowl, or a bowl of a stand mixer fitted with the paddle attachment, combine the butter and sugars. Beat these first 3 ingredients for 3-4 minutes on medium speed until well combined and fluffy.
Next, add your sourdough starter and mix for another 1-2 minutes until combined. Then add the peanut butter, mixing well. Then, add the eggs and vanilla and beat well for an additional 1-2 minutes.
After the wet ingredients are well combined, add the flour, baking soda, baking powder and sea salt to the bowl, mix in the dry ingredients until just combined.
After the flour is slightly incorporated. Add in both kinds of oats, and the inclusions (M&M’s and Chocolate Chips). Mix until the ingredients are just incorporated. If you are worried about overmixing, finish the last couple stirs with a rubber spatula to get it all well combined.
NOTE: at this point you can either let your cookie dough ferment or bake right away. If you plan to long ferment them: Place the cookie dough on the counter for 4 hours and then bake them or you can ferment on the counter for 4 hours and place in the fridge overnight.

To bake the cookies same day or the next day:

Line a baking sheet with parchment paper and scoop the cookie dough onto the pan. Since these are monster cookies you will want them to be big. I like using around 75g of cookie dough per cookie. Or my red cookie scoop (linked above) heaped.
Place 6 cookie dough balls on the parchment-lined baking sheet and place in the preheated oven for 14-16 minutes or until set and slightly brown on the edges.
Let sit on the cookie sheet to cool for 5 minutes before removing them to a cooling rack to finish cooling.
Repeat with the remaining cookie dough.
These cookies stay fresh for 3-5 days in an airtight container. You can freeze them for up to 3 months in an airtight container.

NOTES:

*You might be wondering if you can use chunky peanut butter in place of creamy. I would not recommend substituting chunky for creamy peanut butter. You will find your cookies not to be as tender and soft but drier.
If you are trying to stay away from food dye you can substitute the M&M’s for a chopped-up Hershey’s Milk chocolate candy bar. I did this once and honestly; they are just as good as with M&M’s!
Cold vs. Warm: I tested baking these cookies both with warm cookie dough and cold cookie dough. Both worked. The only difference I would note is the cold dough made for a thicker cookie. So, if you like thicker cookies, I would bake the dough when it is cold.

Recipe makes 21 large cookies.

Soft and Chewy Sourdough Monster Cookies Recipe

5 from 1 vote

A fun sourdough cookie that is packed with peanut butter, oats, chocolate chips and m&ms. Are you ready for how delicious these cookies are?

By: Mariah Nienhuis

Serving Size: 21 large cookies

Print Recipe Pin Recipe

Ingredients

1 cup (240g) butter, softened
1 cup (220g) brown sugar, packed
½ cup (100g) granulated sugar
¼ cup (50g) sourdough starter, active or discard
1 cup (250g) creamy* peanut butter
2 eggs room temperature
2 tsp (10g) vanilla extract
1 cup (120g) all-purpose flour
1 tsp (4g) baking soda
1 tsp (4g) baking powder
½ tsp (3g) sea salt
1 cup (90g) old-fashioned oats
1 cup (90g) quick oats
3 cups inclusions a combination of M&M’s and Chocolate Chips*

Instructions

Instructions for Soft and Chewy Sourdough Monster Cookies

Preheat your oven to 325 degrees. (Skip this step if you are planning to make these cookies long fermented.)
In a large bowl, or a bowl of a stand mixer fitted with the paddle attachment, combine the butter and sugars. Beat these first 3 ingredients for 3-4 minutes on medium speed until well combined and fluffy.
Next, add your sourdough starter and mix for another 1-2 minutes until combined. Then add the peanut butter, mixing well. Then, add the eggs and vanilla and beat well for an additional 1-2 minutes.
After the wet ingredients are well combined, add the flour, baking soda, baking powder and sea salt to the bowl, mix in the dry ingredients until just combined.
After the flour is slightly incorporated. Add in both kinds of oats, and the inclusions (M&M’s and Chocolate Chips). Mix until the ingredients are just incorporated. If you are worried about overmixing, finish the last couple stirs with a rubber spatula to get it all well combined.
NOTE: at this point you can either let your cookie dough ferment or bake right away. If you plan to long ferment them: Place the cookie dough on the counter for 4 hours and then bake them or you can ferment on the counter for 4 hours and place in the fridge overnight.

To bake the cookies same day or the next day:

Line a baking sheet with parchment paper and scoop the cookie dough onto the pan. Since these are monster cookies you will want them to be big. I like using around 75g of cookie dough per cookie. Or my red cookie scoop (linked above) heaped.
Place 6 cookie dough balls on the parchment-lined baking sheet and place in the preheated oven for 14-16 minutes or until set and slightly brown on the edges.
Let sit on the cookie sheet to cool for 5 minutes before removing them to a cooling rack to finish cooling.
Repeat with the remaining cookie dough.
These cookies stay fresh for 3-5 days in an airtight container. You can freeze them for up to 3 months in an airtight container.

Notes

*You might be wondering if you can use chunky peanut butter in place of creamy. I would not recommend substituting chunky for creamy peanut butter. You will find your cookies not to be as tender and soft but drier.

If you are trying to stay away from food dye you can substitute the M&M’s for a chopped-up Hershey’s Milk chocolate candy bar. I did this once and honestly; they are just as good as with M&M’s!

Cold vs. Warm: I tested baking these cookies both with warm cookie dough and cold cookie dough. Both worked. The only difference I would note is the cold dough made for a thicker cookie. So, if you like thicker cookies, I would bake the dough when it is cold.

These cookies are so much fun and are the perfect sweet treat. Let me know below how they turned out for you and if you have any questions. Be sure to sit down with a freshly baked sourdough monster cookie fresh from the oven with a glass of cold milk! You might just be in cookie heaven! Fresh-baked cookies are for sure one of my favorites!

Happy Baking!

Mariah Nienhuis | TheFarmChicken

And I will walk among you, and will be your God, and ye shall be my people.
Leviticus 26:12

Soft and Chewy Sourdough Monster Cookies Recipe

A little bit nostalgia, a lot of deliciousness is packed in these Soft and Chewy Sourdough Monster Cookies. Truly a monster cookie and the perfect addition to your sourdough cookie recipe collection.

Ingredients for Soft and Chewy Sourdough Monster Cookies

Helpful Tools for Making Sourdough Monster Cookies

Frequently Asked Questions:

More Sourdough Recipes to Try:

Pin this for Later:

Soft and Chewy Sourdough Monster Cookies Recipe

Instructions for Soft and Chewy Sourdough Monster Cookies

To bake the cookies same day or the next day:

NOTES: