Make Cookie Dough: Melt the butter in a large mixing bowl, then whisk in the peanut butter until no lumps remain. Add the sugars, and whisk to combine. Add the eggs and vanilla, and whisk until smooth and combined, about 30-45 seconds. Stir in the dry ingredients last. (You will need to use some elbow grease here for it to come together - I promise it will! - or use your mixer for this last bit.)
1 cup salted butter, melted, 3/4 cup + 2 tbsp creamy peanut butter, 3/4 cup dark brown sugar, packed, 3/4 cup granulated sugar , 2 large eggs, at room temperature , 1 and 1/2 tsp vanilla extract , 3 cups all-purpose flour, spooned & leveled or weighed out , 1 tsp baking soda, 1 tsp baking powder, 1/2 tsp salt