This is a building on recipes project so you will need to get your buttercream prepared in advance. If you are using natural food color like I did, juice those vegetables ahead of time too. ( I used tumeric powder for the yellow) I used 7" cake pans to get 6 perfectly even layers. If you do not have 7" cake pans you may use 8" pans for a 4 layer cake
Combine the flax meal with the hot water and let stand for about 5 minutes to thicken
Add the vinegar to the milk to sour
Sift the flours with the baking powder and salt
Cream the vegan butter with the sugar until light and fluffy and this may take about 3-5 minutes on medium to high speed
Add the thickened flax paste while mixing on medium speed, scrape the bottom and sides of the bowl to incorporate evenly, add the vanilla extract
Add about ⅓ of the flour to the creamed mixture then add half of the soured milk
Add another ⅓ of the flour and then the remaining sour milk
Add the last amount of flour and mix just to combine evenly.
Divide the batter evenly into 6 bowls, add your food color to each one. (* I used tumeric powder for the yellow)
Spread the batter into greased and parchment lined cake pans and bake in a preheated 350°F oven for approximately 15-18minutes or until they are springy to the touch when you gently press the centers.
I used 7" cake pans to get 6 perfectly even layers. If you do not have 7" cake pans you may use 8" pans for a 4 layer cake
Meanwhile prepare the buttercream recipe if you have not already
Let the cakes cool completely then proceed as shown in the video above to make the checkerboard design with a set of round cookie cutters. Space them as evenly as possible depending on what size cake layers you are using. Since I had 7" layers I used a 4½" cutter for the first ring and a 2½" cutter for the center ring