Make the cake batter

1. Poke 1 pound of sweet potatoes with a fork. Microwave for 8 minutes until soft. Peel off skin and mash into a puree.

2. Mix the dry ingredients:

   • 290g flour

   • 1 1/4 tsp baking powder

   • 1/4 tsp baking soda

   • 3/4 tsp salt

   • 1 1/2 tsp cinnamon

   • 1/2 tsp nutmeg

   • 1/4 tsp ginger

   • 1/4 tsp allspice

3. Whisk together the wet ingredients:

   • 3/4 cup vegetable oil

   • 1 1/8 cup brown sugar

   • 3/4 cup white sugar

   • 1 1/2 tsp vanilla

   • 2 eggs

   • 1 yolk

   • 1 1/2 cup pureed sweet potato

4. Combine the wet and dry in 3 additions, folding gently.

Make a meringue

1. Whisk 3 egg whites with 1/2 tsp salt.

2. When they begin to look frothy, gradually add 135g of sugar and whisk to stiff peaks.

3. Mix in a splash of vanilla.

Assemble and bake

1. Spread the cake batter in a greased 9" springform.

2. Dollop the meringue on top. Then use a butterknife to create swirls by bringing the batter through the meringue to the surface.

3. Bake for 30-35 minutes at 350°.