Melted unsalted butter, for greasing
1 tablespoon instant coffee granules
100g unsalted butter, melted, cooled
1/3 cup milk
2 eggs, lightly beaten
¾ cup caster sugar
1 cup self-raising flour
½ cup thickened cream
Cocoa powder, to decorate
Lightly grease four microwave-safe mugs (1 ½-cups capacity) with butter.
Dissolve coffee granules in 2 tablespoons boiling water in a small heatproof bowl.
Whisk butter, milk and eggs in a large bowl. Whisk in sugar and coffee mixture. Add sifted flour. Whisk until combined. Divide evenly among prepared mugs.
Place mugs around the edge of the microwave turntable.
Microwave, uncovered, on Medium (50%) for about 6 minutes, or until tops spring back when lightly touched. Remove mugs. Stand for 1 to 2 minutes before serving.
Meanwhile, beat cream in the small bowl of an electric mixer until soft peaks form.
Spoon cream on top of cakes. Dust with sifted cocoa.
TIP! Placing mugs around on the edge of the turntable ensures that the cakes cook evenly. If you prefer, dust cakes with drinking chocolate.