Make the matcha cake:

Cup of Yum
1. Prepare the matcha chiffon cake batter according to the recipe instructions.
2. Transfer the cake batter to a 13" by 18" 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/163°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.

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

Make the vanilla ice cream:

1. Pour the cold heavy cream into a large bowl. Set aside.
2. Separate 6 egg yolks from the egg whites and place the egg yolks into a heat-safe bowl. (Refrigerate or freeze the egg whites for later use).
3. In a bowl, whisk together the egg yolks with sugar, vanilla extract, vanilla bean paste (if using), pinch of salt and set aside.
4. Add the milk to a saucepan and heat over low-medium heat until scalding hot.
5. While whisking the egg yolk mixture, gradually pour in the warmed milk (known as tempering the eggs).
6. Pour the mixture back into the saucepan and cook over low-medium heat, until the custard thickens. When you can draw a line on the back of a spatula, the custard is ready.
7. Pour the custard through a sieve into the cold heavy cream.
8. Give the mixture a stir and cover with a lid/plastic wrap.
9. Place into the fridge to chill for at least 6-8 hours, or overnight.
10. The next day, churn the ice cream according to your ice cream maker's instructions.
11. 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.
12. Freeze the ice cream for at least 6-8 hours, or until frozen solid.

Assemble:

1. Flip the matcha cake upside down so that the parchment layer is on top.
2. Gently peel off the parchment paper from the cake.
3. Slice the cake in half (widthwise) so you end up with two 9" by 13" pieces.
4. Flip and place one half of the cake with the browned side facing up (this will be the interior).
5. Remove the parchment paper from the ice cream slab.
6. Carefully position the ice cream over top of the browned side half of the cake.
7. Top the ice cream with the other cake, with the green (not brown) side facing up.
8. Cover with a lid/plastic wrap and place into the freezer to freeze for a few hours until firm.
9. When ready to serve, trim off the edges using a clean, serrated knife and cut into bars or squares to your liking.