Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.

Gather all ingredients and tools—mixing bowls, measuring cups, and an electric mixer.

In a medium bowl, sift flour with baking powder and whisk together.

In a large mixing bowl, cream together butter, brown sugar, and granulated sugar until light and fluffy (about 2-3 minutes). Scrape down the sides of the bowl.

Add the peanut butter and mix on low speed until fully incorporated.

Add the egg and vanilla extract, then mix on low speed until well combined.

Gradually add the dry ingredients to the wet ingredients, mixing on low speed until just combined.

Roll the dough into 1-inch balls and place on the baking sheet about 2 inches apart.

With a fork, press down on each dough ball to flatten, creating a criss-cross pattern.

Bake in the preheated oven for 8-10 minutes until the edges are lightly golden brown but centers remain soft.

Let cookies cool on the baking sheet for 5-10 minutes before transferring to a wire rack to cool completely.

Enjoy your Classic Peanut Butter Cookies with a glass of milk or your favorite beverage!