Preheat the oven to 325°F. Line 15 cups of two muffin tins with paper liners.
In a medium bowl, whisk together the flour, baking powder, espresso powder, cinnamon, and salt. Set aside.
In a stand mixer with the paddle, cream the butter and sugar on medium speed until light and fluffy(3 minutes). Add eggs, one at a time, and mix just until incorporated. Beat in the vanilla and scrape the bowl again.
Add the flour mixture in three additions, alternating with the milk, beginning and ending with the dry ingredients.
Gently fold in the chocolate chips.
Evenly scoop the batter into the prepared muffin cups.
Bake for 23 to 25 minutes, or until a cake tester inserted in the center comes out clean.
