A chewy, soft-baked peanut butter oatmeal cookie exploding with Reese’s peanut butter cups. No mixer, no dough-chilling, so easy!
- 3/4 cup (95g) all-purpose flour (spoon & leveled)
- 1/4 teaspoon salt
- 1/2 teaspoon baking soda
- 1/2 teaspoon baking powder
- 1/2 cup (115g) unsalted butter, melted
- 1/2 cup (100g) granulated sugar
- 1/2 cup (100g) packed light or dark brown sugar
- 1 large egg
- 1/2 cup (125g) creamy peanut butter (not natural style)
- 2 teaspoons pure vanilla extract
- 2 cups (160g) quick oats*
- 1 and 1/2 cups chopped Reese’s Peanut Butter Cups, divided
- Preheat oven to 350°F (177°C). Line two large baking sheets with parchment paper or silicone baking mats. (Always recommended for cookies.) Set aside.
- Toss the flour, salt, baking soda, and baking powder together in a large bowl. Set aside.
- In a medium bowl, whisk the melted butter, granulated sugar, and brown sugar together until no brown sugar lumps remain. Whisk in the egg, then the peanut butter until combined. Finally, whisk in the vanilla. Pour the wet ingredients into the dry ingredients and mix together with a large spoon or rubber spatula. The dough will be very soft and slick. Fold in the oats and the 1 and 1/4 cups chopped peanut butter cups, reserving the remaining 1/4 cup for later.
- Roll the dough into balls, about 3 Tablespoons of dough each. I highly suggest using a cookie scoop to make it easier. Place 8 balls of dough onto each cookie sheet.
- Bake the cookies for 11-12 minutes. The cookies will look very soft and underbaked. They will continue to bake on the cookie sheet. Remove from the oven and lightly press down on each cookie to slightly flatten, since the cookies will not spread all the way in the oven. Press a piece or two of the remaining chopped peanut butter cups into each cookie. Allow to cool on the cookie sheet for 10 minutes before moving to a wire rack to cool completely.
- Make Ahead & Freezing Instructions: Cookies stay fresh covered at room temperature or in the refrigerator for up to 1 week. Baked cookies freeze well, up to three months. Cookie dough balls freeze well too, up to three months. Bake frozen cookie dough balls for about 11 minutes. No need to thaw them. For more information, read my tips on freezing cookie dough.
- Oats: Do not use old-fashioned style oats (aka whole oats) in this cookie recipe. They are the large-cut oats. You need quick oats, which are more finely ground (and smaller) whole oats.
- Be sure to check out my top 5 cookie baking tips AND these are my 10 must-have cookie baking tools.
Keywords: peanut butter cup oatmeal cookies, peanut butter cup cookies