How to Make It
Make the crepe batter: Combine the eggs, milk, flour, butter, sugar, and salt in a blender and process until very foamy, about 1 minute, scraping down the sides as necessary. Transfer 2 1/2 cups of the batter into a liquid measuring cup.
Add 20 drops red food coloring to the batter in the blender and pulse to combine. Add 15 drops blue food coloring to the batter in the measuring cup and stir to combine. Place both batters in the refrigerator to rest, at least 30 minutes and up to 1 day (this will make the crepes more tender).
Meanwhile, make the frosting: Using an electric mixer, beat the cream cheese and butter on high until light and fluffy, about 4 minutes. Add the powdered sugar, vanilla, and salt and beat on low until just combined, scraping down the sides of the bowl as necessary. Continue to beat on medium until very smooth, about 2 minutes. Set aside at room temperature.
Brush a 10-inch nonstick skillet with butter and heat over medium-low. Spray a 4-inch biscuit or cookie cutter with nonstick cooking spray and place in the center of the skillet. Pour 1 tablespoon of the red crepe batter into the ring and swirl the skillet until it fills the circle. Working quickly, pour blue crepe batter around the outside of cutter, swirling the skillet so that the blue batter sets around the cutter. Gently remove the cutter and cook until the edges of the crepe begin to pull away from the sides of the pan, 2 to 3 minutes. Gently flip the crepe using a spatula and your fingers and continue to cook until underside is dry, 1 to 2 minutes more. Transfer to a plate. Repeat, wiping down the cutter and spraying with cooking spray before every crepe, until you run out of blue batter (about 12 crepes).
Add scant ¼ cup of the red crepe batter to the skillet and swirl so the batter completely covers the bottom of the pan. Continue cooking red crepes until you’ve used all of the red batter (about 12 crepes). Transfer to the plate.
Assemble the cake: Place one red crepe on a large serving plate. Dollop 2 tablespoons of cream cheese frosting onto the crepe and spread into a thin layer, leaving a ¼-inch border along the edge of the crepe. Repeat with all of the red crepes, then begin adding the two-toned crepes. Place in the refrigerator for at least 2 hours before serving.
When ready to serve, top the crepe cake with a dollop of whipped cream, plus strawberries, blueberries, and sprinkles.