Step 1: Bake the Cupcakes
• Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
• In a large bowl, whisk together flour, sugar, cocoa powder, baking powder, baking soda, and salt.
• In another bowl, mix buttermilk, vegetable oil, egg, and vanilla extract. Add this mixture to the dry ingredients and stir until just combined.
• Carefully stir in the boiling water until the batter is smooth (the batter will be thin).
• Pour the batter into the prepared muffin tin, filling each liner about 2/3 full.
• Bake for 18–20 minutes, or until a toothpick inserted into the center comes out clean. Let the cupcakes cool completely.

Step 2: Make the Oreo Frosting
• Beat the softened butter until creamy.
• Gradually add powdered sugar and heavy cream, mixing until smooth. Add vanilla extract and mix well.
• Fold in the crushed Oreo cookies until evenly distributed.

Step 3: Frost the Cupcakes
• Use a piping bag with a large round tip to pipe a tall swirl of Oreo frosting onto each cooled cupcake.

Step 4: Prepare the Chocolate Coating
• Melt chocolate chips and vegetable oil in a microwave-safe bowl, microwaving in 30-second intervals and stirring until smooth.

Step 5: Coat the Cupcakes
• Dip each frosted cupcake upside down into the melted chocolate, letting the excess drip off.
• Place the cupcakes upright on parchment or a rack to set. Refrigerate 15–20 minutes to help the chocolate firm up.