Making the Cookies & Cream Sheet Cake is straightforward. Follow these steps for a successful bake:

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C). Grease and flour a 9×13 inch baking pan.
2. Mix Dry Ingredients: In a large mixing bowl, sift together the flour, sugar, cocoa powder, baking powder, and salt.
3. Combine Wet Ingredients: In another bowl, whisk together the milk, vegetable oil, eggs, and vanilla extract until well combined.
4. Combine Mixtures: Gradually add the wet ingredients to the dry ingredients. Stir until the batter is smooth and no lumps remain.
5. Add Cookies: Fold in the crushed chocolate sandwich cookies until evenly distributed throughout the batter.
6. Pour Batter: Pour the batter into the prepared baking pan, smoothing the top with a spatula.
7. Bake: Place in the preheated oven and bake for 30-35 minutes, or until a toothpick inserted in the center comes out clean.
8. Cool: Remove from the oven and let the cake cool in the pan for 15-20 minutes. Then, transfer it to a wire rack to cool completely.
9. Make the Frosting: In a mixing bowl, whip the heavy cream until soft peaks form. Gradually add powdered sugar while continuing to whip until stiff peaks form.
10. Frost the Cake: Once the cake is completely cool, spread the whipped cream frosting evenly over the top. Decorate with additional crushed cookies if desired.

These steps will guide you in creating this incredible Cookies & Cream Sheet Cake without any hassle.