1-First Step: Begin by gathering all your ingredients and equipment. Read through the entire recipe before starting to ensure you have everything needed. This is especially important for baking, where precision matters. Your butter should be at room temperature (about 65°F), which means it should yield slightly to pressure but still hold its shape. Cold butter won’t cream properly, leading to dense cookies. Similarly, your eggs should be room temperature to emulsify evenly with the butter and sugars.

2-Second Step: In a medium bowl, whisk together 1 1/2 cups all-purpose flour, 1 teaspoon baking powder, 1 teaspoon baking soda, and 1 teaspoon salt until well combined. This ensures even distribution of the leavening agents throughout your flour, which helps the cookies bake uniformly. Set this mixture aside while you prepare the wet ingredients. Measuring flour correctly is crucial spoon it into your measuring cup and level it off with a straight edge rather than scooping directly, which can pack down the flour and lead to dry cookies.

3-Third Step: In a large mixing bowl (or the bowl of a stand mixer), beat 1 cup unsalted butter until smooth and creamy. This usually takes about 1 minute on medium speed. Once smooth, add 1 cup granulated sugar and 1/2 cup packed brown sugar. Cream these together on medium-high speed for 3-5 minutes until the mixture is light and fluffy. This process incorporates air into the dough, which helps create a lighter texture. The mixture should noticeably increase in volume and appear pale in color. Scrape down the sides of the bowl periodically to ensure even mixing.

4-Fourth Step: Add 2 large eggs one at a time to the butter mixture, beating well after each addition. This step is crucial for proper emulsification don’t rush it! Once the eggs are fully incorporated, add 1 cup creamy peanut butter and 2 teaspoons vanilla extract. Beat on medium speed until everything is thoroughly combined. The mixture may look slightly curdled at this point, which is normal when adding peanut butter to creamed butter and sugar. Just continue mixing until smooth.

5-Fifth Step: With the mixer on low speed, gradually add the dry ingredient mixture to the wet ingredients. Mix until just combined overmixing at this stage can lead to tough cookies. The dough will be thick and somewhat sticky. Add 2 cups old-fashioned rolled oats and mix on low speed until evenly distributed throughout the dough. The oats should be visible throughout but completely integrated into the mixture.

6-Sixth Step: Remove the bowl from the mixer (if using) and fold in 1 1/2 cups mini M&Ms and 1 1/2 cups semi-sweet chocolate chips by hand using a spatula or wooden spoon. This gentle mixing method prevents breaking the chocolate chips and ensures even distribution without overworking the dough. If you’d like extra chocolate chips or M&Ms on top for appearance, reserve a small amount before mixing them in.

7-Seventh Step: Cover the dough tightly with plastic wrap and refrigerate for at least 30 minutes. Chilling is essential for Chewy Monster Cookies it prevents overspreading and improves chewiness by allowing the oats to absorb moisture from the dough. The dough can be chilled up to 4 days in the refrigerator, which actually develops the flavors further. If chilling longer than 30 minutes, you may need to let the dough sit at room temperature for about 30 minutes before scooping, as very cold dough can be difficult to portion.

8-Eighth Step: When ready to bake, preheat your oven to 350°F. Line baking sheets with parchment paper or silicone baking mats. This prevents sticking and makes cleanup easy. Using a 65g cookie scoop (or three heaping tablespoons), portion the dough, placing balls about 3 inches apart on the prepared baking sheets. You should fit about 6 cookies per standard baking sheet don’t crowd them or they’ll spread into each other. For more oat-based baking inspiration, check out our Scottish Bannocks Oatmeal Scones recipe.

9-Ninth Step: Bake the cookies for 14-16 minutes until the edges are set and lightly browned. The centers will appear slightly soft and underbaked, but this is exactly what you want they’ll continue cooking on the hot baking sheet and firm up as they cool. Rotate the pans halfway through baking for even browning. Every oven is different, so start checking at the 12-minute mark if you know your oven runs hot.

10-Tenth Step: Remove the cookies from the oven and let them cool on the baking sheets for 10 minutes. This resting period is crucial as it allows the cookies to set completely without breaking apart. If you reserved extra M&Ms or chocolate chips, gently press them into the warm cookies now for a picture-perfect appearance. After 10 minutes, transfer the cookies to wire racks to cool completely. This final cooling step helps achieve that perfect texture crispy edges with a soft, chewy center.