Preheat oven to 350°F. Line the following sized-round pans with parchment rounds, and grease with non-stick cooking spray: 3 8-inch pans, 1 7-inch pan, 2 6-inch pans, 3 4-inch pans.

Mix together all dry ingredients (flour, baking powder, sugar, strawberry powder, and salt) in a stand mixer with a paddle attachment until fully combined.

Mix chunks of room-temperature butter slowly into the dry mix, on a low speed. Continue to mix until no large chunks of butter remain, and the mixture becomes crumbly.

Pour in egg whites, and mix on low until just incorporated. Mix in the sour cream in two installments, on a low speed.

Add in vanilla and oil, and mix at a low speed until fully incorporated. Scrape down the sides of the bowl with a spatula, then beat on low speed for about 15 seconds (the key is to mix until the ingredients are JUST incorporated, so that the batter isn't over mixed). 

If desired, add in pink gel food coloring. Mix the color in by hand using a rubber spatula, scraping the sides and bottom of the bowl part way through. Mix until the batter is evenly colored.

Divide batter evenly between the prepared cake pans, so that they are filled to the same height.

Bake for 30-35 minutes (varies slightly based on pan size), or until a toothpick comes out clean. Allow the pans to cool for 10 minutes, then run an offset spatula around perimeter of the pan to separate the cake from the pan.

Place cake layers into the freezer for 45 minutes, to accelerate the cooling process. Once the layers are fully cooled, carefully flip the pans and remove the layers from the pans.

Use a serrated knife to level the tops of the layers. Set aside.

While the cake layers bake and cool, make the strawberry buttercream frosting.

Beat the butter on a medium speed for 30 seconds with a paddle attachment, until smooth.

Add the strawberry powder, and mix until it's fully combined with the butter.

Slowly add in the powdered sugar, 1 cup at a time. Alternate with small splashes of cream.

Once fully mixed, add in the vanilla extract, lemon juice, and salt, and beat on low until the ingredients are fully incorporated, and the desired consistency is reached. 

If the frosting is too thick, add in additional cream (1 TBSP at a time). If the frosting is too thin, add in more powdered sugar (quarter of a cup at a time).

Wait to add any food coloring until after the cake is filled and crumb coated.

Place 2 cups of frosting in a separate bowl and color green.

In a different bowl, color 1 cup of frosting purple, to make Patrick's shorts.

Color the remaining frosting a brighter shade of pink with pink gel food coloring.

Wait to make these until your cake is crumb coated, and chilling in the freezer or fridge.

To make Patrick's arms and legs, melt the marshmallows in a microwave safe bowl, until they're mostly dissolved (about 1 minutes).

Pour in the strawberry rice krispies, and mix until they're fully coated in marshmallow.

Stack and frost cake layers on a large, greaseproof cake drum, from largest to smallest. Use a dab of frosting to help stick the first cake layer to the board.

Build the cake off center, so that you have room to add Patrick's legs later on.

Add an even layer of buttercream between each cake layer.

Insert a wooden dowel through the center of the cake, to help keep the layers in place as you frost the cake.

Apply a coat of frosting around the cake, to fully cover the cake layers.

Smooth using an acetate sheet, then chill the cake in the fridge (30 minutes) or freezer (10 minutes) until the frosting is firm to the touch.

Make the Strawberry Krispies as the cake chills, and tightly press them together to shape patrick's legs.

Shape his arms around bubble tea straws, and then press the straws into the sides of his body. Chill the cake for 10 additional minutes to help the krispies set in place.

Add a second, thicker layer of pink frosting to the torso, head, arms, and legs of the cake.

Smooth using an acetate sheet.

Add green buttercream around Patrick's bottom half, to make his shorts. Chill again, then pipe purple flowers on top of this shorts.

Use fondant to create his eyes, mouth and eyebrows, and gently press them into place.