1/2 cup (1 stick) butter, melted and cooled slightly
1 teaspoon vanilla extract
3/4 cup mini chocolate chips
Heat oven to 400 degrees F. Grease a 12-cup muffin tin.
In a large bowl, combine flour, sugar, baking powder, espresso powder, cinnamon
and salt. Whisk gently to mix.
In a medium bowl, beat egg lightly. Whisk in milk, melted butter and vanilla
extract. Make a well in center of dry ingredients and pour in milk mixture. Stir
just until evenly blended. Stir in chocolate chips.
Divide batter among 12 greased muffin cups.
Bake for 15 to 18 minutes, or until a
cake tester inserted in center of muffin comes out clean.