Step 1
Preheat the oven to 350 degrees F. Spray a 12-cup muffin pan with nonstick baking spray.
Step 2
In a small saucepan, melt butter. Once melted, remove from heat and add oil and chocolate chips. Whisk together until all chocolate is melted, then add cocoa powder and whisk until combined. Set aside to cool.
Step 3
In a separate bowl, whisk together egg, Domino® Light Brown Sugar, and Domino® Granulated Sugar with a hand mixer for 3 minutes, until pale and fluffy. Then add vanilla extract and continue to mix until combined.
Step 4
Pour chocolate mixture into the eggs and sugar and fold together. Then add flour, baking soda, sour cream, and kosher salt. Mix until all of the dry ingredients into the batter until smooth.
Step 5
Spoon out 3 ½ tbsps of batter into each muffin cup. Bake for 20-22 minutes, until the tops of the muffins are shiny. Let the muffins sit at room temperature for 10 minutes and remove from the pan.