Preheat the oven to 400 degrees F. Combine the milk, sugar, vanilla, zest and eggs in a blender and blend until smooth. Add the flour, butter and salt and blend until completely smooth, about 1 minute. Spray muffin tins well with nonstick cooking spray and pour 1/4 cup batter into each tin, filling about three-quarters full. Bake until puffy and golden on top, about 15 minutes. Remove and let sit on a baking rack for a few minutes. Remove the individual pancakes to a platter. The pancakes will sink slightly in the center. Fill with some of the Apple-Calvados Caramel Sauce and dust with cinnamon powdered sugar.
Apple-Calvados Caramel Sauce:
Melt the butter in a large skillet over medium-high heat. Add the apples and cook, stirring until soft, about 8 minutes. Whisk in the sugar and cook until the sugar melts and thickens slightly. Remove the skillet from the heat, add the calvados, then return to the stove and cook until reduced. Add the heavy cream and cook until warmed through. Finish with the mint.