The Bojon Gourmet

0 Position a rack in the center of the oven and preheat to 400ºF.
1 To make the filling, combine the apples and rhubarb in a very large bowl and add the maple syrup, cornstarch, ginger, vanilla, and salt. Gently toss to coat the fruit evenly, then transfer to an 8 by 10-inch baking pan, 9-inch square pan, or 10-inch ovenproof skillet with at least 2-inch high sides. Place the pan on a rimmed baking sheet to catch any drips, and slide into the oven to bake until the fruit just starts to bubble, 20-25 minutes.
2 To make the biscuits, in a large bowl, combine the oat, sweet rice, and millet flours with the maple sugar, baking powder, and salt. Add the butter and work in with a pastry blender or your fingertips until broken down into the size of small peas. Chill until needed, about 10 minutes.
3 Have the 1 tablespoon cream, the sugar, and a pastry brush (or scrunched-up paper towel) nearby.
4 When the fruit is nearly done, combine the yogurt and remaining 4 tablespoons cream 
in a small saucepan. Place over a medium flame and heat, stirring frequently, until the mixture is hot and steamy, 1–2 minutes (don’t let it boil or it might separate). Quickly but gently stir the hot dairy into the butter/flour mixture, stirring just until combined, evenly moistened and no floury bits remain; do not overstir. Remove the fruit from the oven, give it a gentle stir to redistribute, then use a tablespoon to drop the batter onto the fruit, creating 8–12 rough mounds. Immediately dab and brush the tops with the cream and sprinkle with the sugar.
5 Bake the cobbler until the biscuits are deep golden brown on top and the fruit is bubbling thickly, 20-30 more minutes. Let the cobbler cool for at least 10 minutes to allow the fruit to thicken up and the biscuits to finish baking from residual heat. Scoop into bowls and serve warm, topped with maple sugar or vanilla ice cream. The cobbler is best within a few hours of baking, but leftovers can be refrigerated airtight for up to 3 days. Reheat before serving.