Preheat your oven to 450°F (230°C). Lightly grease four 6-ounce ramekins with butter and dust them with cocoa powder. Set aside.
In a microwave-safe bowl, combine the butter and baking chocolate. Microwave in 30-second intervals, stirring after each interval, until the chocolate is fully melted and smooth.
In a separate large bowl, beat together the eggs, egg yolks, and granulated sugar until light and fluffy. This should take about 2-3 minutes.
Stir in the melted chocolate mixture, vanilla extract, and salt into the egg mixture until well combined.
Gradually fold in the all-purpose flour until just incorporated.
Divide the batter evenly among the prepared ramekins.
Bake for 12-14 minutes, or until the edges of the cakes are firm but the centers are still soft.
Allow the hot cakes to cool in the ramekins for 1 minute, then cover each with an inverted small plate. Carefully turn each one over, allow it to sit for a few seconds and then remove the ramekin.
Top each cake with a scoop of vanilla ice cream and drizzle with magic shell topping. If desired, dust with powdered sugar. Enjoy!
Notes
It's crucial not to overbake the cakes, or you won't have the molten "lava" center. Start checking at 12 minutes to see if they're done.You can prepare the batter ahead of time, pour it into the ramekins, and then refrigerate until you're ready to bake. Just add an extra minute or two to the baking time.The magic shell topping will harden upon contact with the cold ice cream, providing a delightful crunch to contrast with the soft, warm cake.