Combine the milk and cereal in a medium bowl. Let sit for about 20 minutes at room temperature.

Strain the milk through a fine mesh sieve or strainer, collecting the milk in a small bowl. Collect 3/4 cup.

Preheat the oven to 325 degrees F. Spray three 8-inch round cake pans with nonstick spray, line the bottom with parchment paper, and spray again. Set aside.

In a medium size mixing bowl, whisk together the cake flour, baking powder and salt. Set aside.

In the bowl of a stand mixer, fitted with the paddle attachment, beat the butter and sugar on medium-high until light in color and fluffy in texture, about 3 minutes.

With the mixer on medium speed, add the egg whites one at a time, making sure to scrape down the sides and bottom of the bowl between each addition. Continue to beat on medium-high speed for about 2 minutes, until smooth. Add the vanilla extract and stir to combine.

With the mixer on low speed, add 1/3 of the dry ingredients, followed by half of the milk 1/3 of the dry ingredients, the second half of the milk and then the final 1/3 of the dry ingredients. Mix just until combined.

Evenly divide the batter among the three pans and bake for about 20 to 25 minutes, or until a toothpick inserted in the center of the cake comes out with just a few moist crumbs on it.

Remove the cake pans from the oven and let the layers cool in pans for 15 minutes before inverting onto cooling racks to cool completely.

Preheat your oven to 300 degrees F. Line a baking sheet with parchment paper. Set aside.

Pour the Captain Crunch into a medium bowl and crush them a little with your hands. Add the milk powder, sugar, salt, and toss to mix. Add the melted butter and toss to coat. As you toss, the butter will act as glue, binding the dry ingredients to the cereal and creating small clusters.

Spread the clusters on the baking sheet and bake for 15 minutes. Cool completely before using.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter until light and fluffy, about 2 minutes.

With the mixer on low speed, gradually add the powdered sugar. Mix until combined.

Add the cream, salt and clear vanilla. Turn the mixer to medium-high and beat for 5 minutes, until light and fluffy. Set aside.

In a blender or food processor, pulse the Captain Crunch Crumble into fine crumbs.

Add the Captain Crunch Crumble crumbs to the buttercream and stir to combine. The texture will be thick.

In a medium saucepan, whisk together the flour and 1/2 cup of the milk until smooth.

Set over medium-high heat and let cook for about 1 minutes or until slightly thick, stirring frequently.

Whisk in remaining milk and salt. Whisk constantly until the mixture has thickened to the consistency of unset pudding (this can take up to 10 minutes).

Remove from heat and pour the mixture into a shallow dish. Cover the surface of the mixture with plastic wrap

Place in the refrigerator until cool, at least an hour.

When cool, the mixture will be thick like custard. If a film formed on top of the mixture, remove it from the bowl.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and sugar together until light fluffy, about 2 to 3 minutes. Add vanilla and mix well.

Beat in cooled flour mixture one tablespoon at a time on medium-high speed. When all the flour mixture is added, beat on medium-high speed until light and fluffy, about 6 minutes.

Rub a little frosting between your fingers. If the sugar granules remain, beat for 4 more minutes, or until granules cannot be detected with fingers.

Place the first cake layer, top side up, in the center of the cake board or cake plate.

Carefully spread half of the Captain Crunch filling on the cake layer, followed by 1/2 cup of the Captain Crunch Crumble. Pat into place.

Place the second cake layer, top side up, on the fillings and repeat step 2.

Place the final cake layer, top side down, on the second layer of fillings. With the boiled milk frosting, lightly frost the cake to create a crumb coat. Freeze for about 10 to 15 minutes.

After the crumb coat is set, continue frosting and decorating the cake with remaining boiled milk frosting.