S'mores Cake

INGREDIENTS

1 cup

room temperature unsalted butter, plus extra for greasing the pans

2 1/4 cups

all-purpose flour

1/3 cup

cornstarch

2 tsp

ground cinnamon

4 1/2 tsp

baking powder

1/2 tsp

salt

1 3/4 cups

superfine sugar (I used granulated sugar)

2 tsp

vanilla extract

medium eggs, lightly beaten

1 1/4 cups

whole milk

3 oz

dark chocolate, finely chopped (I used semisweet chocolate chips)

1/2 cup

heavy cream

3 tsp

light brown sugar

2/3 cup

egg whites (about 4 large eggs)

2 cups

superfine sugar (I used granulated sugar, which didn't end up dissolving as nicely as superfine would have, but it worked well enough)

1/2 tsp

cream of tartar