Preheat the oven to 200°C/400°F/Gas 6.
In a jug, put in the instant coffee in 60ml of hot water.
In a bowl, add the flour, baking powder, salt, and nutmeg, mix it together.
In a large bowl, whisk together the egg and sugar until combined. Then add the milk, oil, vanilla, and coffee, and whisk until fully combined.
Add the wet ingredients to the dry, and mix until combined.
Spray the doughnut tray with FryLight then add the mixture to each section.
Leave the mixture to sit in the mould for 5 minutes.
Put the doughnuts into the oven and bake for 12 - 15 minutes, until nicely coloured and cooked through.
Check the doughnuts are cooked by using a cake skewer.
Leave until the doughnuts are cool.