Preheat oven to 350°F. Line 2 12-cup muffin pans with liners; set pans aside.

Using a large bowl, whisk together the dry ingredients (flour, cocoa powder, sugar, baking powder, baking soda and chocolate chips) until well combined.

In a separate bowl, whisk together the liquid ingredients (eggs, buttermilk, coffee, vanilla extract, vinegar and canola oil) until well combined. Pour liquid mixture into dry mixture and stir until just combined.

Transfer batter into cupcake liners, filling each liner ¾ full.

Bake for 20-22 minutes, or until a toothpick inserted into the center of a cupcake comes out clean.

Let cupcakes cool in pan for 10 minutes before transferring to a cooling rack until completely cool.

Using a countertop mixer, beat butter on medium speed until light and fluffy (~3 minutes).

Add powdered sugar 1 cup at a time, mixing on low speed after each addition.

Add salt, vanilla extract and milk; mix on low speed until well combined.

Using a double boiler or microwave, melt white chocolate. Pour melted chocolate into frosting. Beat on medium speed for 3-4 minutes, or until well combined. (Note: If you desire a looser frosting, add an additional tablespoon of milk. For a thicker frosting, add an additional ¼ cup of powdered sugar.)

Place large Oreo cookies into a food processor or mini-chopper; pulse until finely chopped. Add chopped cookies to the frosting and mix until well combined.

Using a piping bag fitted with a large star tip, frost each cupcake. Place a mini-Oreo in the center of each cupcake.