In a large bowl or stand mixer, cream together butter and sugar. Mix in egg and vanilla. Scrape bowl as needed. Mix in dry ingredients until thoroughly combined. Add sour cream and cooled coffee, mixing until no streaks remain and all ingredients are fully incorporated. Using a large cookie scoop
, add one scoop to each prepared liner. Bake for 18-20 minutes or until cupcakes are set and a toothpick inserted comes out clean. Cool in pan 5 minutes, then transfer to a wire rack to cool completely.