Step 1

Preheat the oven to 350ºF. Spray a 9x13 baking dish with cooking spray.

Step 2

Combine soy milk and apple cider vinegar. Stir and set aside for at least 5 minutes.

Step 3

Prepare the filling by combining brown sugar and cinnamon in a small bowl. Stir until evenly mixed. Set aside.

Step 4

Sift the flour, cornstarch, baking soda, baking powder, salt and turmeric together in a large bowl. Set aside.

Step 5

In the bowl of an electric mixer, combine the vegan butter and sugar. Beat on medium speed for 3 minutes. Scrape down the sides.

Step 6

Add the oil and beat for another 1-2 minutes until the mixture is light and fluffy.

Step 7

Combine the soured milk, sour cream, and vanilla together in a medium bowl and whisk until smooth.

Step 8

Add the wet ingredients to the butter mixture and beat for 60 seconds. It may look curdled, but that is okay.

Step 9

Turn the mixer to the lowest speed and add the flour. Mix just until combined. The batter will be thick like frosting.

Step 10

Scoop 2⁄3 of the batter into the prepared pan.

Step 11

Sprinkle half of the filling over the batter covering the whole pan in an even layer.

Step 12

Spoon the remaining batter on top of the filling. Top the cake with the remaining filling. Use a butter knife to swirl the filling around on the batter.

Step 13

Bake in the preheated oven for 35-40 minutes or until a toothpick inserted comes out clean.

Step 14

While the cake is baking, warm the milk for the icing for about 30 seconds in the microwave. Add the tea bag to the warm milk and let it cool while the cake bakes.

Step 15

Remove from the oven and cool in the pan. Immediately begin preparing the icing.

Step 16

Combine all of the icing ingredients together in a small bowl and whisk until smooth.

Step 17

Pour over the warm cake and spread to the edges.