Step 1

Preheat your oven to 350°F and line your cupcake pan with 4 liners. Place 1 full Oreo in each of the cupcake cups.

Step 2

In a small, microwave-safe bowl, combine butter, chocolate, and vegetable oil. Microwave for 15 seconds and stir. Repeat until mixture is completely melted and smooth. Set aside to cool slightly.

Step 3

In a small bowl, whisk together flour, cocoa powder, baking powder, and salt. Set aside.

Step 4

In a medium bowl, whisk together sugar, egg yolk, and vanilla until well-combined. Whisk in cooled chocolate mixture until smooth. Whisk in flour mixture until just mixed. Add milk and coffee and whisk until smooth. (Batter will be quite thin.)

Step 5

Spoon or pour batter into your prepared cupcake cups, filling 2/3 of the way full. Discard any excess batter.

Step 6

Bake for 16 to 19 minutes, until a toothpick inserted into the center of the cupcakes comes out clean or with just a few crumbs. Once the cupcakes are cool enough to handle, transfer to a cooling rack to cool completely before frosting, 15 to 20 minutes.

Step 7

Separate 1 Oreo and scrape filling into small bowl. Place both sides of the cookie into a small plastic bag and crush into a fine crumb.

Step 8

To the bowl with the Oreo center, add softened butter and cream cheese. Beat until smooth. Add powdered sugar and cookie crumbs and 1 teaspoon of milk or cream. Beat until sugar is completely incorporated and frosting is fluffy. Add up to 2 teaspoons more of milk or cream if necessary until frosting reaches your desired consistency.

Step 9

Transfer frosting to a piping bag and pipe onto cupcakes.

Step 10

Place chocolate in a small, microwave-safe bowl and microwave in 15-second increments, stirring in between, until smooth. Use a spoon to drizzle over cupcakes or transfer to a small plastic bag and snip off one corner to "pipe" chocolate on.

Step 11

Divide final remaining Oreo in two and quarter one half of the cookie. Garnish each cupcake with one of the quarters and eat the remaining Oreo half.