Preheat oven to 425° and prep a standard muffin tin with 12 liners.

In a large bowl (or stand mixer) mix together coffee vanilla, sugar, eggs, and buttermilk until well combined. Gradually add cooled butter, mixing well as you add it. To this mixture add the flour, cocoa, baking soda, baking powder, and salt, and stir until just combined. Fold in 3/4 cup chocolate chips.

Divide the batter between the 12 muffin liners, then sprinkle remaining 1/2 cup of chocolate chips over the tops of the muffins.

Bake for 5 minutes, then reduce the oven temperature to 350° and bake for 14-15 more minutes, until a toothpick inserted comes out clean. Cool for 10 minutes before removing from pan to keep them from crumbling.

Enjoy immediately while fresh (recommended!) or store in the refrigerator for up to one week.