Preheat oven to 165C.
Line muffin tray with cupcake liners
In a large mixing bowl, mix flour, sugar, cocoa, baking powder, baking soda, and salt.
Mix to combine.
Add milk, vegetable oil, eggs, and vanilla to flour mixture and mix together on medium speed until just combined.
Mix espresso powder with boiling water.
Reduce speed and carefully add boiling water mixture to the cake batter.
Beat on high speed for about 1 minute to add air to the batter.
Fold in chopped oreos into batter.
Fill liners to 3/4 full.
Bake for 12-15 minutes or until a toothpick inserted in the center comes out clean.
Remove from the oven and allow the cupcakes to cool completely before frosting.