• 340 ml (1 ½ cups, minus 1 tablespoon) low-fat milk
  • 1 tablespoon lemon juice (from one lemon)
  • 375 g (3 cups) plain flour
  • 1 tablespoon baking powder
  • ½ teaspoon baking soda
  • ½ teaspoon table salt
  • 140 g (10 tablespoons) unsalted butter, melted
  • 190 g (1 cup, minus 1 tablespoon) granulated sugar
  • 2 eggs
  • 3 tablespoons instant espresso powder
  • 175 g (1 cup) semisweet chocolate chips
  • Grated rind of half an orange
  • ½ cup melted butter
  • ½ cup sugar and 2 teaspoons cinnamon, mixed together

Adjust oven rack to lower middle position and heat oven to 190 C (375 F) degrees. In a measuring cup, pour in the milk and add the lemon juice. Let it sit while you prepare the rest of the recipe, and it will give the milk a chance to ‘sour’. Mix flour, baking powder, baking soda, and salt in medium bowl; set aside.
In a medium bowl mix together the melted butter and eggs, add the egg butter mixture to the dry ingredients and mix very well. Add the espresso powder to the soured milk, and add the milk mixture to the flour butter mix and mix well, a few lumps will stay in the batter – that is ok! Add the chocolate chips and orange rind to the batter and mix.

Spray twelve-cup muffin tin with vegetable cooking spray or coat lightly with butter (or use muffin paper liners. Use large ice-cream scoop to divide batter evenly among cups. Bake until muffins are golden brown, 25 to 30 minutes.

While still warm, remove muffins from tin and dip the tops in the melted butter and then the cinnamon sugar mixture.