Preheat the oven to 325ºF. Line an 8-inch springform pan with parchment paper. Spray with nonstick cooking spray.

In the bowl of a stand mixer fitted with the paddle attachment, beat cream cheese on high until creamy, about 1-2 minutes. Add the sugar and continue beating for another 1-2 minutes. Scrape down the sides of the bowl, add the cornstarch, vanilla, lemon juice, and salt, and beat until incorporated, 1-3 minutes. Beat in the eggs until combined. Try not to overmix.

Pour filling into pan, smoothing out the top. Bake cheesecake for 35-40 minutes, or until center appears nearly set when shaken. Transfer the cheesecake to a wire rack and run a knife around the edges. Allow to cool for at least 2 hours before covering cheesecake and chilling in the freezer for about 30 minutes.

Preheat oven to 350ºF. Line two 8-inch pans with parchment paper and spray with nonstick cooking spray.

In a mixing bowl, whisk together the flour, baking powder, baking soda, and salt until combined; set aside.

In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and sugar together on medium speed until lightened and creamy. Beat in the eggs, one at a time, until combined, scraping down the sides and bottom of the bowl as needed. Beat in the sour cream, vanilla, and almond extract on medium speed.

Pour the dry ingredients into the wet ingredients and mix until combined. Add the buttermilk and mix until just combined, scraping down the sides and bottom of the bowl as needed.

Divide batter evenly among two bowls. Tint one half of the batter with the red food coloring and the other with blue food coloring. Pour each batter into separate parchment-lined 8-inch baking pans. Bake for 18-20 minutes or until a toothpick inserted in the center comes out clean. Allow to cool in the pan for at least 15 minutes before transferring to a wire rack to cool completely.

In the bowl of a stand mixer fitted with the paddle attachment, beat the butter and salt together on high until fluffy and pale in color, about 4-5 minutes. Decrease speed to low and slowly add the powdered sugar. Add the vanilla extract, almond extract, and heavy cream and beat until combined. Increase speed to medium-high and beat until light and fluffy, about 4 minutes.

Place blue cake layer on a pedestal or plate. Spread on a thin layer of buttercream, then place the cheesecake layer on top. Add another thin layer of buttercream on the cheesecake, then place the red cake layer on top. Frost the entire cake to seal in the crumbs; chill for at least 30 minutes.**

Divide remaining buttercream into three separate bowls. Tint one bowl red, and another bowl blue.*** Remove cake from the fridge, and use an offset spatula to spread thick patches of red and blue buttercream all around the cake. Fill some of the areas with white buttercream. Smooth the frosting around the cake as the colors begin to blend together. If there are empty patches, feel free to go over them with more frosting until you get the desired watercolor effect you’re looking for.

Add sprinkles to the top of the cake, focusing on the border.

Cake will keep covered in the refrigerator for up to 5 days. Allow to sit at room temperature for 10 minutes before slicing and serving.