Birthday Cake Ice Cream Sandwiches

For key visual steps, refer to the body of the post.

Prepare the confetti birthday cake:

1. Make the Perfect Swiss Roll Cake according to the recipe instructions (note: only use 50g granulated sugar total) and fold in 2 tablespoon of rainbow confetti sprinkles into the cake batter prior to baking.
2. Transfer the cake batter to a 13" by 18" prepared baking sheet lined with parchment paper and smooth the surface with an offset spatula.
3. Tap the pan a few times to release any trapped air bubbles.
4. Bake the cake for 8-10 minutes at 375°F/191°C, or until the top of the cake is dry and springy to the touch.
5. Remove from the oven and let it cool completely on a wire rack.

Make the confetti/birthday cake ice cream:

1. Make the vanilla ice cream according to the Matcha Ice Cream Sandwiches recipe.
2. Add/stir in 2 tablespoon of confetti sprinkles into the ice cream in the last few minutes of churning.
3. Transfer the churned ice cream to a 9" by 13" baking tray lined with parchment paper and use an offset spatula to smooth out the surface.
4. Freeze the ice cream for at least 6-8 hours, or until frozen solid.

Assemble:

1. Flip the cake upside down so that the parchment layer is on top.
2. Gently peel off the parchment paper from the cake.
3. Cut the cake in half width-wise, so you end up with 2 x 9" by 13" cakes.
4. Place one half of the cake with the browned side facing up onto a piece of parchment paper in a 9" by 13" baking tray or pan.
5. Add the slab of frozen confetti birthday cake ice cream onto the cake.
6. Layer the second half of the cake with the browned side facing down on top of the ice cream.
7. Cover with a lid/plastic wrap and freeze until firm.
8. When ready to serve, trim off the edges using a clean, sharp serrated knife and slice into bars or squares to your liking.