Preheat the oven to 450°F with a 10-inch cast-iron skillet on the middle rack.
In a blender, combine the milk, eggs, almond flour, millet flour, sweet rice flour, vanilla extract, cinnamon, and salt. Pulse until completely smooth.
Carefully remove the skillet from the oven. Add the butter, swirling the pan to melt and coat the bottom but not the sides of the pan (you want the batter to creep up the sides)
Carefully pour the batter into the center of the skillet and gently return the skillet to the oven.
Bake until the edges and center puff up and turn golden brown, about 20 minutes.
Meanwhile, prepare the kumquats. Combine the water, sugar, and honey in a small saucepan over medium heat. Cook, stirring, until the sugar melts, 2-3 minutes. Add kumquats and reduce heat to low. Cook, stirring occasionally, for 6-8 minutes, until the kumquats soften. Use a slotted spoon to transfer the kumquats from the syrup to a parchment-lined plate or baking sheet and set aside. Reserve the syrup for another use.
Combine the crème fraîche and vanilla paste in a small bow and chill until serving.
Serve the dutch baby warm straight from the oven* topped with powdered sugar, honeyed kumquats, vanilla crème fraîche, and toasted almond slices.
Notes
*The dutch baby will be most impressively puffed up straight from the oven. After a bit of time out of the oven, it will begin to deflate, but still taste delicious.
This nutritional information has been automatically calculated, and as such, may be incomplete or inaccurate. Please reference the specific ingredients you use for the most accurate nutritional information.