Step 1: Preheat and Prepare : Preheat your oven to 350°F (175°C). Line a 12-cup muffin pan with paper cupcake liners. Set out your ingredients so everything is at room temperature for best results.

Step 2: Mix Dry Ingredients : In a bowl, whisk together flour, cocoa powder, baking soda, baking powder, and salt. Set aside.

Step 3: Cream Butter and Sugar : In a large mixing bowl, beat butter and sugar together until light and fluffy (about 2–3 minutes). Add the eggs one at a time, beating well after each. Mix in vanilla extract.

Step 4: Combine Wet and Dry Mixtures : Add the dry ingredients in three parts, alternating with buttermilk. Mix gently on low speed until just combined — don’t overmix. Stir in hot water (or coffee) to loosen the batter; it should be slightly thin and glossy. Fold in crushed Oreo pieces.

Step 5: Bake the Cupcakes : Divide the batter evenly among the cupcake liners (about ¾ full). Bake for 18–20 minutes, or until a toothpick inserted into the center comes out clean. Allow the cupcakes to cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.

Step 6: Make the Whipped Topping : In a chilled bowl, beat heavy whipping cream with an electric mixer on medium speed until it begins to thicken. Gradually add powdered sugar and vanilla extract. Continue beating until stiff peaks form (do not overwhip). Fold in finely crushed Oreos if desired.

Step 7: Frost and Decorate : Spoon or pipe the whipped topping over cooled cupcakes using a piping bag or a spatula. Garnish with mini Oreos, cookie crumbs, or half an Oreo on top for that perfect cookies-and-cream finish.