Reese’s Pieces Oatmeal Cookies

There’s something about the combination of peanut butter and oats that feels like pure comfort to me. Maybe it’s the way the oats add a bit of chewiness to every bite or how the peanut butter candy shells bring just the right amount of crunch. Either way, these Reese’s Pieces Oatmeal Cookies check all the boxes for a truly satisfying treat. They’re thick, buttery, and packed with sweet and salty goodness—perfect for an afternoon pick-me-up or a late-night indulgence (because let’s be honest, who can resist a warm cookie fresh from the oven?).

I love how simple these cookies are to make, but the flavor is anything but ordinary. The soft and chewy oatmeal base gives them a hearty texture, while the Reese’s Pieces add that signature peanut butter taste with a fun pop of color. Plus, since they’re made with pantry staples, I don’t have to make a special grocery run when a craving strikes. Just a few minutes of mixing, a short bake time, and suddenly my kitchen smells like pure nostalgia—sweet, toasty, and completely irresistible.

These cookies also make a great treat to share. Whether I’m baking up a batch for a family movie night, packing them in lunchboxes, or bringing them to a potluck, they always disappear fast. There’s just something about that peanut butter-oatmeal combo that keeps everyone coming back for more. And honestly, I don’t blame them! Grab a glass of milk and get ready to enjoy the perfect balance of chewy, crunchy, and downright delicious.

Equipment

• Large bowl and mixer or stand mixer
• Small bowl
• Silicone spoon
• Baking sheet
• Cooling rack

Ingredients

• 1/3 cup shortening – Helps create a tender, chewy texture in every bite.
• 1/2 cup packed light brown sugar – Adds a rich, caramel-like sweetness and extra softness.
• 1/3 cup granulated sugar – Balances the brown sugar with a touch of crispness around the edges.
• 1 egg – Binds the dough together and gives the cookies structure.
• 1 teaspoon vanilla extract – Enhances the flavors with a warm, aromatic sweetness.
• 1 cup all-purpose flour – Provides the perfect base for a sturdy yet soft cookie.
• 1/2 teaspoon baking soda – Helps the cookies rise and stay light and chewy.
• 1/2 teaspoon salt – Brings out the sweetness and balances the flavors.
• 2 tablespoons milk – Adds moisture and ensures a soft, tender cookie.
• 1 1/2 cups rolled oats – Gives the cookies a hearty, chewy texture with a hint of nuttiness.
• 1 (10 oz) package Reese’s mini pieces – Brings the perfect pop of peanut butter flavor and crunchy candy coating!

Step-by-Step Instructions

You can find a printable recipe card at the bottom of this post.

1. Preheat the heat oven to 350 degrees. Lightly grease a baking sheet.

2. Add the shortening, brown sugar, and granulated sugar to a large bowl, and beat until fluffy. Then beat in the egg and vanilla extract.

3. Stir the flour, baking soda and salt in a small bowl.

4. Alternate beating in the flour mixture, then milk to the sugar mixture.

5. Stir in the oats and Reese’s Pieces.

6. Drop heaped spoonfuls of dough onto the prepared baking sheet, then gently press down.

7. Bake for 13-15 minutes or until lightly browned.

8. Allow to cool for 10 minutes on the baking sheet, then transfer to a wire rack to cool completely.

Tips for Perfect Reese’s Pieces Oatmeal Cookies

• Use Room Temperature Ingredients – Allow the egg and milk to come to room temperature before mixing. This helps everything blend smoothly and evenly.

• Don’t Overmix the Dough – Overmixing can make the cookies tough. Mix just until the ingredients are incorporated for soft, chewy cookies.

• Measure Flour Correctly – Spoon the flour into your measuring cup and level it off with a knife. Packing it in can lead to dry cookies.

• Use Old-Fashioned Rolled Oats – Quick oats will make the cookies too soft, while steel-cut oats won’t soften enough. Rolled oats provide the perfect chewy texture.

• Press the Dough Lightly – Gently pressing the dough before baking helps the cookies spread just the right amount.

• Bake Until Just Golden – The cookies should be lightly browned around the edges but still soft in the center. They will continue to set as they cool.

• Let Them Cool on the Baking Sheet – Allowing the cookies to rest for 10 minutes before transferring them to a wire rack helps them firm up without becoming too crisp.

• Store Properly for Freshness – Keep cookies in an airtight container at room temperature for up to a week, or freeze them for longer storage.

• Make Them Extra Peanut Buttery – For even more peanut butter flavor, add 2 tablespoons of creamy peanut butter to the dough.

• Mix Up the Add-Ins – While Reese’s Pieces are the star, you can add chocolate chips, chopped peanuts, or even a sprinkle of sea salt on top for a fun twist!

Get Creative!

• Chocolate Lover’s Version – Swap out half of the rolled oats for mini chocolate chips or drizzle the finished cookies with melted chocolate for an extra indulgent treat.

• Peanut Butter Explosion – Stir in 2 tablespoons of creamy peanut butter into the dough for an even richer peanut butter flavor. You can also add chopped peanuts for extra crunch!

• Monster Cookie Twist – Turn these into monster cookies by adding in some mini M&M’s and a handful of chopped pretzels for a sweet and salty combo.

• Make Ice Cream Sandwiches – Sandwich a scoop of vanilla or peanut butter ice cream between two cookies and freeze for a delicious homemade ice cream sandwich.

• Drizzle with Caramel or Peanut Butter Glaze – Take these cookies to the next level by drizzling them with a simple caramel sauce or a peanut butter glaze after baking.

• Oatmeal Bar Variation – Instead of dropping cookie dough onto a baking sheet, press it into a greased 9×9-inch pan and bake for 20-25 minutes to make soft and chewy cookie bars.

• Add a Sprinkle of Sea Salt – A light sprinkle of flaky sea salt on top before baking enhances the sweet-salty balance and makes the flavors pop.

• Make Them Mini – Scoop out smaller portions of dough and reduce the baking time for bite-sized treats perfect for snacking or sharing.

• Try Different Candy Mix-Ins – Swap out the Reese’s Pieces for peanut butter chips, toffee bits, or chopped peanut butter cups for a fun variation.

• Holiday-Themed Cookies – Use seasonal Reese’s Pieces colors (orange and brown for fall, red and green for Christmas, or pastels for Easter) to make them festive for any occasion!

Serving & Storing

Serving Suggestions

• Fresh from the Oven – These cookies taste best warm when the edges are slightly crisp, and the center is soft and chewy. Enjoy them with a cold glass of milk!
• Dunk & Enjoy – Pair with a hot cup of coffee or tea for a cozy afternoon treat.
• Ice Cream Pairing – Serve alongside a scoop of vanilla, peanut butter, or chocolate ice cream for an extra indulgent dessert.
• Make a Cookie Sundae – Crumble a warm cookie over a bowl of ice cream and drizzle with chocolate or caramel sauce.
• Sweet Party Platter – Arrange these cookies with peanut butter cups, chocolate chip cookies, and brownies for the ultimate dessert tray.

Storing for Freshness

• Room Temperature Storage – Keep cookies in an airtight container at room temperature for up to one week to maintain their softness and flavor.
• Layer with Parchment Paper – If stacking cookies in a container, place parchment paper between layers to prevent sticking.
• Refrigeration (Optional) – While not necessary, you can store cookies in the fridge for a slightly firmer texture. Let them come to room temperature before eating.

Freezing for Later

• Freeze Baked Cookies – Place cooled cookies in a freezer-safe container or bag, separating layers with parchment paper. Store for up to 3 months and thaw at room temperature when ready to enjoy.
• Freeze Cookie Dough – Scoop dough onto a baking sheet and freeze until solid. Transfer to a freezer-safe bag and store for up to 3 months. When ready to bake, place frozen dough on a baking sheet and bake as usual, adding 1-2 extra minutes to the bake time.