Could you tell me how to prepare Berry Cheesecake Poke 'Box' Cake?
Here's a recipe for Berry Cheesecake Poke 'Box' Cake:

Ingredients:

• 1 vanilla cake mix, prepared according to package
• 2 cups strawberry, stems removed
• 8 oz cream cheese, softened
• 14 oz sweetened condensed milk
• 1 cup blackberry, mashed
• 1 cup raspberry, mashed
• 8 oz frozen whipped topping, thawed
• graham cracker, crumbled, for topping
• strawberry, sliced, for topping

Instructions:

1. Preheat oven to 350°F (180°C).
2. Prepare your favorite plain vanilla cake recipe or use a prepared box and follow its instructions.
3. Using the back of a wooden spoon, poke at least 3 rows of 4 holes in the cooked cake, making 12 holes total.
4. In a large bowl, mash the strawberries with a potato masher or fork until mashed to a pulp. 
5. Add the cream cheese and condensed milk, whisking until there are no large lumps. 
6. Add the mashed blackberries and raspberries; stir just once or twice so the colors remain differentiated.
7. Pour the mixture over the cake and let settle into the holes for about 10 minutes. Some of the mixture will still stay on top, which is okay.
8. Spread the whipped topping evenly over the cake. Sprinkle graham crackers on top and add sliced strawberries or other fresh berries. 
9. Chill the cake for at least 3 hours or up to overnight.

Enjoy your Berry Cheesecake Poke 'Box' Cake!