Preheat the oven to 400℉. Line the muffin tin with paper liners and set aside.
In a large bowl, combine flour, brown sugar, cocoa, baking powder, baking soda and salt. Stir to mix. Make a well in the center of the flour mixture.
1 ¾ cups flour, ½ cup packed brown sugar, ¼ cup cocoa, 1 teaspoon baking powder, 1 teaspoon baking soda, ¼ teaspoon salt
Combine the warm water, canola oil, red wine vinegar, vanilla and egg and stir well with a whisk.
1 cup warm water, ¼ cup canola oil, 1 teaspoon red wine vinegar, 1 teaspoon vanilla extract, 1 large egg
Add ½ cup semisweet chips to the oil mixture and then add that to the flour mixture, stirring until just combined.
½ cup semisweet mini chocolate chips
Place liners in a 12-muffin tin and coat liners with cooking spray. Divide batter evenly among the muffin cups. Sprinkle the tops of each muffin with a few mini semisweet chips.
Additional mini semisweet chocolate chips for tops of muffins
Bake at 400℉ for 15 minutes or until a wooden pick inserted in the center comes out clean. Cool in pan for 5 minutes, then remove to wire rack to cool. Serve warm or at room temperature.