1/2 cup cornstarch
1/2 cup millet flour
1/2 cup white rice flour
1/4 cup tapioca flour
1/2 cup almond meal
1/2 cup sorghum four
2 teaspoons baking powder
1 1/2 teaspoons xanthan gum
1 1/2 teaspoons salt
2 cups sugar
1 teaspoon cinnamon
1/2 teaspoon nutmeg
1 cup pecans
2 very ripe bananas
1 cup canned crushed pineapple
1/4 cup agave nectar
1 tablespoon vanilla extract
1 cup canola oil
3 eggs, beaten
for the frosting...
1 1/2 cups sugar
3/4 cup water
6 egg whites
1/4 teaspoon salt
1/4 teaspoon + 1/8 teaspoon cream of tartar
1 1/2 teaspoons vanilla extract
Preheat your oven to 350 degrees. Butter two 8-inch cake pans. Line the bottom of each pan with a piece of parchment paper (here's the link with some helpful hints) and butter the parchment paper.
Spread the pecans in a pie pan or rimmed baking sheet. Toast in the oven for about 10 minutes or until very lightly toasted and fragrant. Remove from the oven and allow the pecans to cool. When cool, finely chop the nuts (I don't enjoy huge chunks of nut in my cake, so I chop the pecans as fine as possible with a large chef knife. But you could rough chop the pecans if you prefer the larger nuts in your cake.)
In a large bowl, combine the cornstarch, all of the flours, almond meal, baking powder, xanthan gum, salt, sugar, cinnamon, and nutmeg. Whisk to blend. Mash the bananas in a large bowl and add the pineapple, agave nectar, and vanilla. Stir until smooth. Add the oil and eggs to the dry ingredients and blend until smooth. Add the chopped pecans and the banana-pineapple mixture and stir until blended.
Divide the batter between the two prepared cake pans. Cover each pan with aluminum foil and bake for 50 minutes. Uncover and bake for another 10 minutes. Remove the cakes from the oven and allow to cool in the pans.
Meanwhile, make the frosting...
In a small saucepan, combine the sugar and water. Bring to a boil over medium-high heat, whisking to dissolve the sugar. Cook the mixture until it reaches 239 degrees on a candy thermometer.
While the sugar and water are heating, beat the eggs whites in a stand mixer fitter with the whisk attachment until opaque. Add the cream of tartar and continue to beat on high until thick and foamy. Add the vanilla and beat.
When the sugar reaches 239 degrees, immediately pour the hot sugar mixture into the eggs whites in a slow steady stream while the mixer is running. Continue beating the icing until stiff, glossy peaks form (about 5 to 7 minutes).
Place one of the cakes on a large plate. Top with about 1/3 of the frosting. Top with the second cake and frost the top and sides of the stacked cakes. Garnish with some whole pecans or toasted coconut if desired.
recipe slightly adapted from Blackbird Bakery Gluten-Free cookbook.