First Step: Preheat your oven to 350°F (175°C). Line a 24-cup muffin tin with paper or silicone liners to ensure easy removal and even baking.

Second Step: In a large bowl, beat together granulated sugar, vegetable oil, eggs, and vanilla extract until the mixture is pale and fluffy, about 2-3 minutes using an electric mixer. Add sour cream or yogurt and mix until fully incorporated.

Third Step: In a separate bowl, whisk together all-purpose flour, baking powder, and salt. Sifting helps prevent lumps and ensures even rising.

Fourth Step: Gradually add the dry ingredients to the wet mixture, alternating with milk, beginning and ending with the dry ingredients. Mix gently on low speed to avoid overmixing, which can result in tough cupcakes.

Fifth Step: Carefully fold in roughly chopped Oreo cookie pieces, leaving some chunks intact to maintain texture contrast throughout the cupcakes.

Sixth Step: Divide the batter evenly among the liners, filling each about two-thirds full. Bake for 18-22 minutes, or until a toothpick inserted comes out clean. For gluten-free versions, check at 17 minutes to avoid dryness.

Seventh Step: Let the cupcakes cool fully on a wire rack before applying frosting, preventing the buttercream from melting.

Eighth Step: Using a mixer, beat cold unsalted butter until fluffy, about 3-4 minutes. Gradually add powdered sugar in batches, mixing on low speed until combined, then increase speed briefly. Mix in finely crushed Oreos, heavy cream (or milk), and vanilla extract, beating on high for 1 minute until smooth and creamy.

Final Step: Pipe the cookies and cream frosting onto each cooled cupcake using a piping bag fitted with a large star tip or a zip-top bag with the corner cut off. Garnish with whole or crushed Oreos for a finishing touch. Serve immediately or store appropriately for later enjoyment.