In a large bowl use a whisk to combine the flour, sugar cocoa powder and baking powder.
Add in 1 cup (250ml) warm water, oil, vanilla extract and 1 cup (250ml) coffee.
Combine the mixture well and pour into a greased microwave-safe cake mold or glass bowl. SEE NOTE 2
Microwave the cake for roughly 10 minutes (this cooking time is based on my microwave which is 1000 Watt so your bake time may vary).This means that your baking time will vary by either a few minutes more or less depending on your microwave.
Stop every 4 minutes and check your bake by using a toothpick to pierce the cake. If the toothpick comes out clean, the cake is done. It’s also important to stop and check because timing can differ slightly depending on the microwave.
You will know when the cake is done when it's firm to the touch in the middle and it pulls away from the sides of the pan. SEE NOTE 3
Take care not to overcook or the cake will become dense, rubbery and dry Remove from the microwave and allow to cool in the pan for 5 minutes before turning out on a cooling rack
Cool completely and frost as you prefer.