Start by preheating your oven to 350°F.

Sift the flour and baking powder together in a bowl, then whisk until combined.

In another mixing bowl, cream the softened butter and both sugars together until light and fluffy. Optionally, add a pinch of sea salt to enhance the flavor.

Incorporate the peanut butter, mixing well until combined.

Add the egg and vanilla extract, blending until thoroughly mixed. Gradually introduce the flour mixture until everything is combined.

Shape the dough into 1-inch balls and arrange them on a baking sheet lined with parchment paper.

Flatten each cookie using a fork in a criss-cross fashion.

Bake in the preheated oven for approximately 10 minutes, or until they are slightly golden.

Let the cookies cool entirely on the baking sheet; they need time to firm up before transferring.