1. Preheat your oven to 350 degrees, grease a mini doughnut pan well.
2. Melt the butter in a small saucepan, pour 1/4 cup of it (that’s 4 tbsp) into a jug and set it aside.
To the saucepan containing the remaining (2 tbsp of) butter, add the cinnamon, dark brown sugar, milk, cornstarch and vanilla extract. Heat just until it bubbles then take it off the heat and pour around 3/4 tsp of the mixture into the bottom of each cavity of the doughnut pan.
3. Add the egg and milk to the jug containing the butter and whisk together.
4. Stir together the flour, granulated sugar, baking powder, salt and grated nutmeg in a medium bowl. Pour in the contents of the jug and stir together until just combined, the mixture may look slightly lumpy, don’t over mix it. Spoon or pipe the batter into the doughnut pan, filling each cavity about 2/3 full.
5. Bake the doughnuts for 8 minutes and turn out a wire rack. Once they’re cool, glaze with cream cheese frosting:
6. Cream the frosting ingredients together in a bowl. Pour into a small sandwich bag and cut the very tip of one of the corners off. Pipe the frosting in zig-zags onto the cooled mini doughnuts. Sprinkle on the chopped pecans / walnuts if using.
*My mini doughnut pan can only make 12 doughnuts at a time, so I washed the pan after baking and turning out the first 12 doughnuts. Then I just refilled the pan with the remaining cinnamon-caramel + doughnut batter and baked them to get a total of 24 doughnuts.