For the Chocolate Pudding Layer:
2 teaspoons instant espresso powder
1 1/2 cups boiling water
1/3 cup natural cocoa powder
1/3 cup (about 2 1/3 ounces) granulated sugar
1/3 cup (about 2 1/3 ounces) packed dark brown sugar

For the Salted Caramel Cake Layer:
Non-stick baking spray
1/3 cup (about 2 1/3 ounces) granulated sugar
2 tablespoons light corn syrup
1 tablespoon water
6 tablespoons heavy cream
6 tablespoons (3 ounces) unsalted butter, cut into 6 pieces
3/4 cup (about 3 3/4 ounces) all-purpose flour
2 teaspoons baking powder
1/2 teaspoon salt
1/3 cup (about 2 1/3 ounces) packed dark brown sugar
2 large egg yolks
2 teaspoons pure vanilla extract
1/3 cup whole milk
1 teaspoon Coarse sea salt, such as Maldon (See Notes)