1 ¾ cups all-purpose flour
¾ cup white sugar
2 teaspoons baking powder
½ teaspoon baking soda
3 tablespoons unsweetened cocoa powder
¾ cup dark or semi-sweet chocolate chips, plus more for sprinkling
1 cup milk
⅓ cup vegetable oil
1 large egg, lightly beaten
2 teaspoons instant espresso (this intensifies chocolate flavor; you won't taste coffee at all)
2 teaspoons hot water
1 teaspoon vanilla
Preheat oven to 400 degrees and lightly grease or line a standard muffin tin. Dissolve instant espresso granules in the hot water and set aside.
Combine dry ingredients and chocolate chips in a large bowl. In a separate bowl, whisk together milk, oil, egg, the dissolved espresso granules, and vanilla, then add to the dry ingredients. Stir until just combined (batter should be lumpy).
Distribute batter evenly into muffin tins and sprinkle additional chocolate chips on top. Bake for 17 to 19 minutes, or until muffins have risen and are springy.