For the cake:
3/4 cup sorghum flour, plus more for sprinkling in the pan
1 cup buckwheat flour
1/2 cup millet flour
1/2 cup plus 1 tablespoon tapioca flour
1/4 cup arrowroot flour
2 teaspoons baking powder
1 1/2 teaspoons xanthan gum
1 teaspoon baking soda
1 teaspoon fine sea salt
1 1/4 cups unrefined cane sugar
2/3 cup melted coconut oil
1 tablespoon ground flaxseeds
1 tesapoon vanilla extract
1 teaspoon maple extract
2 cups vegan buttermilk (see Note)
1 1/2 cups fresh raspberries
1 1/4 cups nondairy chocolate chunks
1 tablespoon cider vinegar

For the icing:
1/4 cup maple syrup
1/4 cup unsweetened nondairy milk
2 tablespoons vegan buttery spread
1/4 teaspoon fine sea salt
1 tablespoons sorghum flour
1/4 teaspoon maple extract
1 1/2 cups confectioners’ sugar, sifted

To make the cake, preheat the oven to 350 degrees F. Lightly oil a 10-inch (12 cup) Bundt pan, using a pastry brush to thoroughly coat the bottom and side of the pan. Sprinkle with sorghum flour, tapping out the excess.

Put the buckwheat flour, sorghum flour, millet flour, 1/2 cup of the tapioca flour, and the arrowroot flour, baking powder, xanthan gum, baking soda, and salt in a large bowl. Whisk to combine.

Put the sugar, coconut oil, flaxseeds, maple extract, and vanilla extract in the bowl of a stand mixer, with the paddle attachment, or a large bowl. Turn the stand mixer or a hand mixer on medium-low speed. Beat until well combined.

Turn the mixer to low speed. Alternately add the flour mixture (in three additions) and the vegan buttermilk (in two additions), beginning and ending with the flour mixture, beating well after each addition. Turn off the mixer.

Put the raspberries, chocolate chunks, and the remaining 1 tablespoon of tapioca flour in a medium bowl. Toss until the chocolate chunks and raspberries are well coated. Add the mixture to the batter, gently stirring until evenly distributed. Immediately stir in the cider vinegar until just combined.

Scrape the batter into the prepared pan using a rubber spatula, smoothing the top. Bake in the centre of the oven for 40 to 45 minutes, until a toothpick inserted in the center of the cake comes out clean. The cake will be golden brown, begin to pull away from the sides of the pan, and will spring back when lightly touched.

Let cool in the pan for 10 minutes, then invert the cake directly onto a serving dish. Cool to room temperature before preparing the icing.

When ready, to make the icing, put the maple syrup, nondairy milk, vegan buttery spread, and sea salt in a medium saucepan. Bring to a boil, and boil for 2 minutes. Reduce to a simmer, add the sorghum flour, and cook for 1 more minute. Remove from heat and add the maple extract, mixing well. Add the confectioners’ sugar. Mix well. Set aside to cool for about 30 minutes.

To serve, spoon the icing over the cake, letting it run down the sides, completely coating the cake. Let stand about 15 minutes to set. Serve at room temperature. Leftovers taste best stored in a sealed container for up to 3 days at room temperature.

Note: To make vegan buttermilk, put 1 tablespoon of cider vinegar in a liquid measuring cup, then pour in enough nondairy milk to make 2 cups total. Let stand about 5 minutes, until curdled.