Cream the butter and sugars together on medium speed using a mixer. Add the peanut butter, then egg, then vanilla, scraping down the sides as necessary.

In a separate bowl combine the baking soda and flour.

Slowly add flour mixture into butter-sugar mixture, being careful not to overmix the dough. Once dough is fully combined use a large spoon to stir in Reese’s Pieces.

Roll cookie dough into balls (2 tablespoons for small cookies, ¼ cup for large cookies) then refrigerate for at least 30 minutes.

Preheat oven to 350 degrees. Arrange dough on an ungreased cookie sheet and bake until cookies just start to brown, about 8-10 minutes for small cookies or 10-15 minutes for large cookies. Let cool fully on wire rack. <br>Mandatory: taste at least one during the cooling process :-)