Checkerboard Cake with cooked Buttercream Frosting

Ingredients:

For the vanilla sponge:
Eggs : 3
Sugar : 1/2 Cup
Plain flour :  1/2 Cup  minus 1 tbsp
Cornflour : 1 Tbsp
Vanilla extract : 1 Tsp

For the chocolate sponge:
Eggs : 3
Sugar : 1/2 Cup
Plain flour :  1/2 Cup  minus 3 tbsp
Cocoa powder : 2 Tbsp
Cornflour : 1 Tbsp
Vanilla extract : 1 Tsp

For the Frosting:
Butter, at room temp : 1 Cup
Sugar: 1 Cup (I used 1/2 Cup granulated sugar and 1/2 Cup icing sugar)
Milk : 1 Cup
Plain flour/All purpose flour : 4 Tbsp
Vanilla extract : 1 tsp
Food color

Method:

For the sponge (Vanilla & Chocolate):

Preheat the oven to 180C
Prepare two 8 inch cake tins.

Sift the dry ingredients together and keep it aside.
Beat the eggs and sugar together till mousse like and almost tripled in volume. This will take about 10-12 mins of beating on high using an electric beater.
Fold  the dry ingredients into the egg mixtures, carefully. The mixture will deflate a little,don't worry.
Pour into the prepared tin and bake for 25-30 mins or till the skewer inserted comes out clean.
Cool in the tin for 10 mins and then invert it onto a cooling rack and cool completely.

Frosting and Filling:

Mix milk and flour in a medium saucepan, without any lumps. Cook over medium-high heat, stirring continuously, until it becomes a very thick smooth paste. This will take 3-4 minutes. Remove from heat and let it cool completely.

Beat the cooled flour/milk mixture with 1 tsp of vanilla on high speed for 4 minutes. It will become smooth now.

In a separate bowl combine the 1 cup sugar and 1 cup softened butter together with a electric mixer. Blend on high for 4 minutes. Add the flour/milk mixture to this and beat on high speed for 3-4 minutes until super fluffy. In between you can add food color too. The frosting is ready now.

Assembly:

Cook the 2 cakes. Instead of cutting it horizontally, this time we need to cut it vertically.

Once the cakes are cooled completely, level them such that both cakes are of same height or thickness.
We need to cut the cake into 3 concentric squares. As I've used 8" cake, we need to cut 6" and 4" squares from this.
Measure 1" from each side and place tooth picks. Now we can cut the outer square and repeat the same until we get 3 concentric squares. (If you like to make round cakes, you can do this using 6" and 4" bowls, lids or cookie cutter)

Repeat the same steps with the other cake too. 

Now, interchange the middle square . While you do so, be careful and try to spread some frosting so that the cake squares sticks together.

Apply a light coating of frosting over one layer of cake and carefully place the second layer on top.
Cover the top and sides with the frosting and decorate as you desire.