Finally a dessert recipe in which the purple of my sweet potatoes really shines.
Recipe based on this one: Stokes Purple Sweet Potato Pirate Pie. I've changed some ingredients and have suggestions for other changes.
2 cups purple sweet potatoes, baked and mashed or pureed
1/2 cup sugar (or less if you prefer)
1/2 cup whole milk or cream or coconut milk (a little more might help with mixing)
2 Tbsp rum (or water or juice)
1/2 tsp vanilla extract
2 large eggs
2 Tbsp cornstarch (less probably works; the final texture was a bit gummy)
3 tsp unsweetened cocoa powder
1 tsp ground cinnamon
1/2 tsp ground ginger
1/2 tsp ground mace
1/4 tsp ground allspice
1/4 tsp ground cloves
1/2 tsp salt
1 prepared chocolate pie crust (or graham cracker, or make your own)
Prepare the sweet potatoes (about 3 medium) ahead of time. Rinse and gently scrub to remove soil. Bake 50-60 minutes in a 400 degree oven; pierce with fork first to prevent bursting. (Obviously the length of time varies depending on the size of the potato. Best to do this the day before.) When cooled, remove skins and mash with a potato ricer, or you can put them in the food processor to get a really smooth texture.
When ready to make the pie, preheat oven to 325. Measure out 2 cups of mashed sweet potatoes. In a separate bowl whisk together the eggs, rum, vanilla and milk. Add the sugar and mix well. Add the sweet potatoes and mix thoroughly.
In a small bowl mix together all the dry ingredients. Add the dry ingredients to the wet and incorporate.
Fill the pie crust, smooth down the top, and bake 50-60 minutes, until a toothpick inserted in the center comes out clean. Cool and eat either at room temperature or refrigerated (with whipped cream or vanilla ice cream if you like).
Note: these are really dense-fleshed sweet potatoes. I found that I had to use the food processor to remove all the lumps, which probably adds to the gumminess of the final product, but cutting down the cornstarch might help with that. Contrary to my previous experience with pumpkin or even orange sweet potato pie, I was plopping the batter into the pie crust with a big spoon rather than ladling or pouring it, and it was hard to tell for sure when it was completely cooked because it started out just as thick as when it was done.
Nevertheless, it tasted great. The chocolate crust and cocoa additions were my idea; going by the cacao-roasted sweet potato recipe I posted before, I knew that chocolate pairs well with the purple sweet potatoes, and it worked here too. Obviously you can use another type of crust if you prefer, and eliminate the cocoa (that would also make the purple color pop more). This recipe should also work fine with orange sweet potatoes.
My only other baking experience with these since the purple-turned-green cake has been muffins in which I tried adding some yogurt and lemon juice to balance the alkalinity of the baking powder. Except the recipe used molasses for sweetening, which turned the muffins a brown that looked just like chocolate but didn't taste like it, completely disguising whatever color they would have been otherwise. I'll try again with white sugar or honey. But I think pie is the best bet, really.