Cinnamon Mocha Sheet Cake

Ingredients

• 1 teaspoon baking soda 
• 1 cup brown sugar 
• 0.3 cup butter 
• 2 cups confectioners' sugar sifted
• 2  eggs lightly beaten
• 2 cups flour all-purpose
• 0.5 teaspoon ground cinnamon 
• 2 tablespoons espresso powder instant
• 1 tablespoon milk as needed
• 3 tablespoons strong coffee decoction brewed
• 3 tablespoons cocoa powder unsweetened
• 1 teaspoon vanilla extract 
• 1 cup water 
• 1 cup sugar white

Equipment

• frying pan
• baking sheet
• sauce pan
• oven
• whisk
• mixing bowl
• wire rack
• microwave

Directions

1. Preheat oven to 350 degrees F (175 degrees C). Grease a 10x15-inch jelly roll pan.
2. Melt 1 cup butter in a saucepan over medium heat.
3. Whisk in 1/3 cup cocoa powder, water, and espresso powder; mix until smooth.
4. Combine white sugar, brown sugar, flour, 1 1/2 teaspoon cinnamon, and baking soda in a mixing bowl.
5. Pour in the butter-cocoa mixture, vanilla extract, 1/2 cup milk, and eggs.
6. Mix until fully incorporated.
7. Pour the batter into the prepared baking sheet
8. Bake in the preheated oven until the cake springs back when touched lightly with a finger, about 18 minutes. Cool the cake in the pan on a wire rack.
9. To make the icing, melt 1/4 cup butter in a saucepan or in the microwave.
10. Transfer melted butter to a mixing bowl.
11. Whisk in 3 tablespoons cocoa powder, coffee, 1/2 teaspoon cinnamon, and 1 tablespoon milk. Slowly mix in the sifted confectioners' sugar and beat until smooth; add milk as needed to reach the consistency you like.
12. Spread the icing over the cooled cake. For easier serving, score the icing before cutting the cake: mark lines as a guide before you start to cut, and divide the cake into 32 pieces.