Preheat the oven to 350°F. Spray two 8-inch round cake pans (or three 6-inch) with cooking spray and dust with all-purpose flour, discarding any extra flour (or spray with baking with flour cooking spray).

In a large bowl, combine the whole wheat flour, all-purpose flour, baking soda and cinnamon. Set aside.

In the bowl of your stand mixer with the beater attachment, beat the brown sugar and eggs until foamy and thoroughly beaten.

Meanwhile, in your blender or food processor, purée the apple slices and oil together. Pour into the beaten eggs/sugar of your stand mixer.

Next, purée the carrots and orange juice together. Pour into the beaten eggs/sugar mixture of your stand mixer.

Add in the vanilla extract, mustard and ginger to your stand mixer and beat on low until all of the wet ingredients are combined.

Pour the dry ingredients into the wet ingredients of your stand mixer and stir until just combined.

Equally separate out into your cake pans (about 2 1/4 cups of batter per 8" pan or 1 1/2 cups of batter per 6" pan).

Bake for 20-30 minutes, until a cake tester comes out clean and the edges are light golden brown.

Allow the cakes to cool for five minutes in the pan before carefully flipping out onto a cooling rack to cool completely.

Meanwhile, to assemble your icing, beat butter, yogurt and vanilla extract together until combined. Add in the powdered sugar until combined.

Assemble the cake and decorate as desired.