Line two cupcake pans with cupcake liners and preheat the oven to 350 degrees.
In a medium sized bowl, beat butter on medium speed with an electric mixer until smooth and creamy. Add cookie butter and mix until incorporated. Add sugar and vanilla; mix well. Add eggs one at a time, mixing well after each.
In another bowl, combine flour, baking powder, and salt. Add half of the flour mixture and half of the buttermilk to the sugar mixture. Mix until just combined. Repeat with the second half of the flour and buttermilk and mix well.
Fill cupcake liners about 2/3 full of batter. Bake for 20 minutes or until lightly golden brown on top. Let the cupcakes cool completely before frosting.