1-Preheat and Prep: Heat your oven to 350°F (177°C). Grease a 9×13-inch pan well or line with parchment for easy lift-out. This sets you up for flawless release. Takes 5 minutes.

2-Whisk Dry Ingredients: In a bowl, whisk 2.5 cups cake flour, 2 tsp baking powder, 0.5 tsp baking soda, and 1 tsp salt. No lumps means even rise. Quick 1-minute job!

3-Cream Butter and Sugar: Beat softened 0.75 cup butter on high for 1 minute until creamy. Add 1.5 cups sugar, beat 2 minutes for fluff. Scrape bowl often. You want pale and voluminous.

4-Add Egg Whites and Wet: Beat in 4 room-temp egg whites for 2 minutes until foamy. Mix in 0.75 cup sour cream and 1 Tbsp vanilla. Room-temp keeps batter smooth, no curdling.

5-Combine and Fold Oreos: On low, add dry mix in thirds, alternating with 0.75 cup milk. Stop when just combined, no overmix! Gently fold in 1.25 cups chopped Oreos. Batter should be thick but pourable.

6-Bake to Perfection: Spread into pan, smooth top. Bake 32-35 minutes until toothpick pulls clean. Edges pull from sides? Perfect doneness. Cool fully in pan, about 3 hours. Patience pays off!

7-Make Frosting: Beat 6 oz softened cream cheese 1 minute. Add 0.75 cup confectioners sugar and 1 tsp vanilla, beat 2 minutes smooth. On low, pour in 1.5 cups cold heavy cream. Whip on high to stiff peaks, 1-2 minutes. Magic happens fast!

8-Frost and Garnish: Save 1 cup plain frosting for piping. Fold 1 cup chopped Oreos into rest. Spread thick on cooled cake. Pipe zigzag border with reserved frosting using offset spatula or bag. Top with mini Oreos. Chill 1 hour or serve room temp.

9-Final Step – Serve: Slice into 12 generous pieces. Pairs great with milk or coffee. Store as below. Enjoy the crunchy, creamy bliss!