Grease ramekins/custard cups and place them on a baking sheet.
Microwave chocolate and oil in a large microwaveable bowl for 30 seconds. Whisk it well until chocolate is completely melted. Microwave for an additional 10 seconds if needed to completely melt chocolate.
Whisk eggs, egg yolks, and sugar on high till it is well blended. Stir in the flour and chocolate mixture until smooth.
Divide the batter into 4 ramekins. Place the ramekins in the oven along with the baking sheet and bake for 13-14 minutes. The cake will firm on the sides but the center will be runny.
Let it stand for a minute. Carefully run small spatula or knife around cakes to loosen and invert onto dessert plates. Dust with confectioners sugar and serve immediately!