Preheat your oven to 325 degrees F. Spray three 8-inch round pans with nonstick spray, line the bottom with parchment paper and spray again. Set aside.

In a medium bowl, combine buttermilk and ovaltine powder. Set aside

In a medium bowl, whisk together flour, salt and cocoa powder. Set aside.

In the bowl of an electric mixer, fitted with the paddle attachment, combine the butter and sugars. Beat on medium speed until light and fluffy, about 2 minutes. Scrape down the sides of the bowl and mix again for another minute.

Add the eggs, one at a time, being sure to mix and scrape down the sides of the bowl between each addition.

Add the sour cream and mix until combined. (Don't worry if the mixture looks slightly curdled).

With the mixer on low speed, add 1/3 of the flour mixture, followed by 1 cup of the buttermilk mixture. Continue with another 1/3 of the flour, the second half of the buttermilk and then the remaining buttermilk. Stir until combined.

In a small bowl, combine the vinegar and baking soda. The mixture will bubble. Add the mixture to the cake batter and stir on low until combined. Scrape down the sides of the bowl and mix again for another 20 seconds.

Divide the batter evenly between the prepared pans (21 ounces in each of the 8-inch pans). Bake for about 35-40 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs on it.

In a small bowl, whisk together the cream and the malt powder. Don't worry if the mixture is a little thick.

In the bowl of an electric mixer fitted with the paddle attachment, beat the butter on medium-high speed until light and fluffy.

Stream in the melted chocolate and mix until well combined, making sure to scrape down the sides and bottom of the bowl.

With the mixer on low speed, gradually add the powdered sugar.

Add the vanilla, followed by the cream and malt mixture.

Turn the mixer to medium-high speed and beat until light and fluffy, about 3 to 5 minutes.

In a small bowl, whisk together the cream and the malt powder. Don't worry if the mixture is a little thick.

In the bowl of an electric mixer fitted with the paddle attachment, beat the butter on medium-high speed until light and fluffy.

With the mixer on low speed, gradually add the powdered sugar.

Add the vanilla, followed by cream and malt mixture.

Turn the mixer to medium-high speed and beat until light and fluffy, about 3 to 5 minutes.

Place the first cake layer top side up, in the center of the cake board. Gently spread 1/2 of the chocolate malt buttercream over the cake layer (about 1 - 1.5 cups). Remember to get eye level with the cake to make sure you spread the buttercream evenly.

***If you want to use a little of the chocolate malt buttercream to create an ombre look, similar to mine, reserve 1/3 cup of the buttercream.

Crush one cup of the malt balls and sprinkle about half over the buttercream and press into place with your hand. Don't crush the malt balls too much. Just a little. Big pieces are okay.

Place the second cake layer on top of the buttercream. Evenly spread the other half of the chocolate malt buttercream over the cake layer and sprinkle with more malt balls.

Place the final cake layer, top side down, on the buttercream.

Using the vanilla malt buttercream, apply a thin layer of buttercream over the entire cake. This is the crumb coat. Freeze the crumb coated cake for 15 minutes.

Once the crumb coat is set, continue to frost the cake with the remaining vanilla malt buttercream and chocolate malt buttercream.