Preheat oven to 425F and line a muffin tray with liners.

In a bowl, add the flour, brown sugar, baking powder, baking soda, milk powder, and salt— whisk to combine.

To the warm milk, add the instant coffee and cocoa powder and mix until you have a smooth paste. Add the milk mixture, vegetable oil, egg, and yogurt. Whisk into the dry ingredients, until there are no traces of flour — do not overmix. Fold in the chocolate chips with a rubber spatula.

Scoop the batter into the liners. Bake for 5 minutes. Reduce the oven to 350F and bake for an additional 13 to 15 minutes or until a toothpick inserted into the center comes out clean.

Make the filling: In a saucepan over medium heat, mix the heavy cream, chocolate chunks, instant coffee, and salt. Once combined, remove from heat and set aside.

Remove the muffins from the baking pan and allow to cool completely before filling: scoop out a little from the center and pour in the filling. Enjoy!