In a large skillet over medium-high heat, whisk together the milk, sugar, vanilla, garlic, and onion. Whisk of the reserved milk and sweetener in a large bowl. In a separate bowl, whisk together the flour, salt, and baking soda until well combined. Pour the batter, along with the sauce, batter mixture, and mixture into a piping bag. To make the dough (this is the part you've got to prepare for an early spring day), prepare a 3-quart baking dish that's 6 inches, but does not have a rim and is at least 11 inches in diameter. Cut the crust to size by cutting and filling it out with a small, round-bottomed platter. In a larger pan, melt the butter or powdered sugar on high, then set aside to cool as you go. Cook the dough until lightly browned on a lightly floured surface, about 20 minutes. Add the cornstarch and whisk to combine. Place the egg yolks in a large bowl and beat until stiff peaks form, about 5 minutes. Transfer the custard to a bowl and stir in the remaining ingredients.