7-year-old: Because it always has a tie, got it?

Ice-cream cake roll

(Adapted from Smitten Kitchen)

4 large eggs, separated
1/8 tsp salt
1/8 tsp cream of tartar
50 g sugar
50 g dark brown sugar
1 tsp vanilla extract
1 1/2 tbs water
30 g Dutch-processed cocoa powder (more to dust)
45 g cake flour
1/2 tsp baking powder
2 pints vanilla ice-cream
200 g dark chocolate + 200 g heavy cream (optional)
Colorful sprinkle (optional)

1. Preheat oven to 400 F.
2. Line a 10″ x 15″ baking pan with parchment paper.
3. In a medium bowl, beat the egg whites until foamy.
4. Add the salt and cream of tartar.
5. Slowly add sugar and beat until stiff peaks form. Set aside.
6. In a large bowl, beat egg yolks.
7. Slowly add brown sugar, and beat until thicken.
8. Add the vanilla extract and water, and mix until incorporated.
9. Use a spatula to gently fold the whites into the yolk.
10. Sift the cake flour, cocoa powder, and baking powder in the egg mixture.
11. Gently fold the dry ingredients into the egg mixture.
12. Spread the batter into the lined pan.
13. Bake for 7 minutes.
14. Run a knife around the edge of the cake.
15. Sift cocoa powder on top of the cake.
16. Place a large dishcloth over the cake.
17. Place a cooling rack over the cloth.
18. Flip to unmold the cake.
19.  Gently peel the parchment paper off the cake.
20. Use a serrated knife to cut the edge of the cake.
21. Roll the cake tightly within the dishcloth.
22. Let it cool to room temperature, about 20 mins.
23. Meanwhile, leave the ice-cream at room temperature to soften a bit.
24. Gently unroll the cake.
25. Scoop ice-cream and drop all over the cake.
26. Use a small spatula to smooth the ice-cream.
27. Roll the cake back up.
28. Wrap the ice-cream cake in plastic wrap and freeze over night.
29. Optional: before serving, heat heavy cream, and pour over chocolate pieces to make chocolate ganache. Pour chocolate ganache all over the ice-cream cake.
30. Optional: use colorful sprinkles on top if you want.