Prepare muffin pan by spraying with a nonstick cooking spray or lining with paper liners.
Break unsweetened chocolate into small pieces. Add butter and microwave for 30 seconds. Continue microwaving for 15 seconds at a time until butter is melted. Stir until chocolate is fully melted. Pour chocolate mixture into a large mixing bowl and allow to cool slightly.
2 oz unsweetened chocolate, ½ cup butter
Stir in sugar. Then add eggs, sour cream, milk and vanilla.
1 cup sugar, 2 eggs, ¾ cup sour cream, ½ cup milk, 1 teaspoon vanilla
In a separate bowl, combine flour cocoa powder, baking powder, baking soda and salt.
2 cups flour, ⅓ cup unsweetened cocoa powder, 2 teaspoons baking powder, ½ teaspoon baking soda, ¼ teaspoon salt
Fold flour mixture into chocolate mixture.
Fold in chocolate chips.
1 cup semisweet chocolate chips
Scoop into prepared muffin tin.
Bake in a preheated 400° oven for 15-18 minutes.
Allow muffins to cool for 2-3 minutes. Remove from muffin tin and continue cooling on a baking rack.
Notes
Substitutions and Variations:
Substitute plain Greek yogurt for the sour cream
Use dark chocolate chips in place of the semisweet chocolate chips
Stir in one cup of chopped pecans or walnuts
Tips:
Use fresh baking powder - baking powder can lose its effectiveness and if old, your muffins might not rise properly.
Fully preheat your oven - I use a separate oven thermometer in my oven to make certain my oven has reached the proper temperature. My preheat light often turns off before the oven has reached full temperature so I always give it extra time.
Do not overmix batter. Just stir until everything is mixed in. Over stirring can cause tough muffins.
Use an ice cream scoop for even sized muffins. Plus it makes putting the batter in the tins easy peasy!