Preheat the oven to 375°F.

Line a large muffin pan with paper or use a vegetable spray to coat the cups.

In the bowl of your mixer, whip the cream cheese until smooth.

Add the eggs, vanilla and sugar and whip until smooth and creamy.

Place Cheesecake filling in a pastry bag, and set aside.

In a large mixing bowl, whisk together the cocoa, flour, sugar, baking powder, baking soda, espresso powder, salt.

In a medium-sized mixing bowl, whisk together the eggs, milk, vanilla and vinegar.

Add the wet ingredients, along with the melted butter, to the dry ingredients, stirring to blend; don't over mix the muffins, its okay if there are some lumps.

Scoop the batter into the prepared muffin tin.

With your pastry bag full of cheesecake filling, place the tip of the pastry bag into the top of the batter and squeeze in enough to increase the volume of the muffin by about a quarter of the original size.*

Bake the muffins for 20 to 25 minutes, or until a cake tester inserted in the center of a muffin comes out clean.

Remove the muffins from the oven, and allow to cool on a wire rack for 10 minutes before serving.