Marble Sheet Cake

upgrade by adding a rich chocolate ganache into the mix in this Marble Sheet Cake.
Ingredients
1 ounce milk chocolate melted and set aside this is for the chocolate cake batter but needs to be done first so it can cool slightly
Vanilla Cake Batter
1 cup 2 sticks or 226g unsalted butter room temperature1½ cups 300g granulated sugar3 large eggs room temperature1 tablespoon vanilla extract½ cup 122 5g whole milk room temperature½ cup sour cream room temperature2 cups 250g allpurpose flour1 teaspoon baking powder½ teaspoon kosher salt
Chocolate Cake Batter
3 tablespoons cocoa powder½ teaspoon baking soda
Ganache Swirl
2 ounces semisweet chocolate melted4 tablespoons heavy whipping cream
Instructions
Melt 1 ounce of milk chocolate in the microwave in 30second increments until mostly melted. Stir until all chunks are fully melted. Set aside.
Vanilla Cake
In a large bowl with a handheld mixer or in the bowl of a stand mixer mix together the butter and granulated sugar on high until fluffy.
Add in eggs and vanilla and mix until combined.
Add in the room temperature milk and sour cream and mix until fully combined.
Add flour baking powder and salt to the batter and mix until JUST combined. There should be no lumps and the batter will be on the thicker side like pancake batter.
Chocolate Cake
In a separate bowl add one cup of the vanilla cake batter. To that add 3 tablespoons of cocoa powder 12 teaspoon baking soda and the 1 ounce of chocolate that was melted in the beginning.
Stir well. The chocolate batter will be very thick.
Ganache Swirl
In a small bowl add the 2 ounces of semisweet chocolate and heavy whipping cream.
Heat for 1 minute in the microwave and then stir for about a minute. The mixture should come together and be thicker and glossier when done.
Assembly
Pour the vanilla cake into a 1015inch baking pan coated with nonstick spray.
Place the chocolate cake batter into a pastry bag and cut off about an inch from the top.
Pipe the chocolate batter onto the vanilla batter in a zigzag pattern starting at one end. You may also dollop the chocolate batter in as much of the pattern as you can if you dont have a pastry bag.
Take a kitchen knife and do another zigzag pattern the opposite way horizontally.
Now pour the ganache in the same loose zigzag swirl pattern and run the knife through one more time.
Bake for 1622 minutes or until when pressed the center of the cake bounces back. If you insert

a toothpick it should be removed with some crumbs but not wet batter.