Preheat the oven to 425º.

Spray or butter 4 ramekins or 4 oven-proof custard cups (3/4 cup capacity).

Place them on a baking sheet.

In the microwave melt the chocolate with the butter together in a large bowl on high for 1 minute, or until it is ALMOST melted.

Remove it from the microwave and stir with a wire whisk until the chocolate is completely melted. You don’t want to overcook the chocolate mixture.

Stir in the confectioner’s sugar and espresso powder until well-blended.

Whisk in the eggs and egg yolks.

Whisk in the flour.

Divide the batter evenly into the 4 prepared ramekins or cups.

Bake at 425º for 13-14 minutes, no longer! The sides should be firm and the center should be soft.

Transfer the baking sheet from the oven to a wire rack and let them stand for 1 minute.

Then carefully run a knife around the sides to loosen them.

Using a potholder, invert the cakes onto your dessert dishes.

Serve the lava cakes immediately plain or sprinkle the tops with confectioner’s sugar. These are wonderful too with whipped cream on top or ice cream and/or fruit!