Make the Confetti Cake

1. Preheat the oven to 375°F (190°C). Prepare two 9×13 inch baking pans with parchment paper in the bottom and spray the sides.
2. In a medium sized bowl, combine the flour, baking powder and salt. Set aside.
3. Beat the butter and sugars just until combined and smooth.
4. Add the egg and mix until well combined.
5. Add the vanilla extract and milk and mix until well combined. Batter will look a little curdled.
6. Add the flour mixture and mix just until well combined.
7. Divide the batter evenly between the two cake pans. I used a food scale to do that accurately, but you could measure with cups as well. Spread the batter evenly. It’ll be VERY thin. Sprinkle about two tablespoons of sprinkles on top of each of the cakes, so 4 tablespoons (1/4 cup) total. Bake for 7-10 minutes or until a toothpick comes out clean.
8. Allow to cool mostly in the pan, then turn out onto a cooling rack that’s large enough for the full cake. You’ll want to line the cooling rack with parchment paper and lightly spray the parchment with non-stick baking spray, so that it doesn’t stick. The “tops” of the cakes will end up being the outside of the ice cream sandwiches and ideally they’ll look nice, so you don’t want them to stick to the parchment paper.
9. Prior to building the ice cream sandwiches, put the cakes into the freezer for about 20-30 minutes (you can freeze them for longer if you want to do that ahead of time).

Build the Ice Cream Sandwiches

1. Use a round biscuit cutter/cookie cutter/something similar that’s about 2 3/4 inches in diameter to cut circles out of the two cake layers to make the rounds for the sandwiches. You should get about 12 per cake layer, depending on the size of your cutters.
2. Place the little cake rounds back in the freezer to stay firm while you work. If they aren’t firm while working with them and adding the ice cream, they are more likely to break apart.
3. Add about 1/4 cup (4 tablespoons) of ice cream to the top of a cake and spread evenly. I used the back of a spoon to spread it around. I found it was easiest to work with the ice cream when it was still firm and right out of the freezer. The softer it is, the more it melts out from the between the cakes when you place them back in the freezer. Work quickly. Top the ice cream with a second cake and place the sandwich back into the freezer.
4. Continue working with the cakes and ice cream until you’ve made all of the ice cream sandwiches. Allow them to freeze for 2-3 hours so that the ice cream is fully frozen, then dip the sides into the remaining 1/2 cup of sprinkles. I spread the sprinkles out onto a plate and rolled the ice cream through them.
5. Put the finished sandwiches back in the freezer until ready to serve.