Chocolate sweet potato torte

This is the third dessert we served at our pre-wedding dessert party. I got the recipe from Vegetarian Times, but I modified it a little. The biggest change I made was reducing the sugar by 1/3. Everyone agreed that it was sweet enough this way. The sweet potato flavor is pretty subtle, and you won't be able to taste it in a bite containing any of the chocolate topping, but it definitely makes a difference in the texture. As far as I can tell, this lasts indefinitely in the fridge. And it's gluten-free.

Chocolate sweet potato torte

1 cup sugar, divided
1 cup cooked sweet potato, mashed
1 cup almond flour
1/2 cup unsweetened cocoa powder
1/8 tsp salt
4 large eggs (three separated)
2 oz bittersweet chocolate (I used one square of unsweetened baker's chocolate and one square of semi-sweet)
2 tbsp milk or soy milk

Spray nonstick cooking spray on a 9-inch pie dish and preheat the oven to 375.

Blend sweet potato, 1/2 cup sugar, almond flour, cocoa powder, and salt in a food processor until smooth. Add three egg yolks and one whole egg and pulse to combine. Transfer to mixing bowl.

Beat three egg whites in electric mixer until they hold soft peaks. Add remaining 1/2 cup sugar and beat until it holds stiff peaks.

Fold 1/3 of egg whites into sweet potato mixture with spatula. Gently fold in remaining egg whites. Pour batter into pie dish and bake for 45 minutes or until toothpick inserted in the center comes out clean. Allow to cool, completely.

Fill a small saucepan about 1/3 with water. Place a glass mixing bowl on top and turn heat to medium. (Note: this is my version of a double boiler. It might be terribly unsafe, but it works for me.) Put the chocolate into the bowl. Stir as it melts. You might have to adjust the heat if the boiling gets vigorous. When the chocolate has melted, stir in the milk or soy milk. Spread chocolate over top of torte. Let stand until chocolate sets.