Prepare Dry Ingredients: In a bowl, mix flour, cocoa powder, baking powder, salt, and instant coffee.
Combine Wet Ingredients: In another bowl, whisk melted butter, oil, and sugar until well-combined. Add the egg and whisk until pale.
Mix and Add Flavorings: Stir in half the milk, yogurt, and vanilla.
Incorporate Dry Mix: Slowly add the dry ingredients to the wet mixture. If the batter is too thick, add the remaining milk. Fold in choco chips.
Pour and Bake: Pour the batter into a parchment-lined muffin tray. Bake at 370°F for 5 minutes, then reduce the temperature to 270°F and bake for 15 more minutes.