Bake the yellow and strawberry cakes in 8x2 inch pans as per the instructions on the boxes. The boxes will yield 2 strawberry cakes and 2 yellow cakes but I only used 1 vanilla cake for my layers and froze the extra one to enjoy later.
Allow the cakes fully cool to room temperature.
While the cakes are baking and cooling, prepare the frosting.
Also prepare the crunchy topping: Add freeze dried strawberries and Nilla wafers in a food processor and pulse until you have fine crumbs.
Transfer to a large bowl.
Add melted butter and whisk together until you have a crumbly mixture.
To assemble, place one strawberry cake on a serving dish.
Spread buttercream on top evenly with a spatula.
Place the vanilla cake on top.
Spread buttercream on top evenly with a spatula.
Place the final strawberry cake on top.
Optional: Place thinly sliced strawberries on top of the icing between each layer. Make sure the strawberries have been patted dry with paper towels.
Chill cake in fridge for 20-30 minutes to make it firm. This keeps the layers from sliding when you ice the entire cake next.
Use a spatula to frost the entire cake smoothly in buttercream frosting.
Cover entire cake in crunchy topping.
To decorate, fill a piping bag with icing and attach a big star tip (Tip 1M).
Pipe swirls on top of the cake.
Place a single strawberry on top of each swirl. Enjoy.