Preheat the Oven: Preheat your oven to 425°F (220°C). Grease and flour individual ramekins or small baking cups.
Melt the Chocolate and Butter: In a heatproof bowl, melt the chopped chocolate and butter together. This can be done using a double boiler or by placing the bowl in the microwave and heating in short bursts, stirring between each burst until smooth. Allow the mixture to cool slightly.
Prepare the Batter: In a separate bowl, sift together the flour and powdered sugar. Add the eggs and egg yolks to the chocolate-butter mixture, one at a time, mixing well after each addition. Stir in the vanilla extract and a pinch of salt. Gently fold in the sifted flour and powdered sugar until just combined. Be careful not to overmix.
Fill the Ramekins: Pour the batter into the prepared ramekins, filling each about 2/3 full.
Bake: Place the filled ramekins on a baking sheet and bake in the preheated oven for 10-12 minutes. The edges should be set, but the center should still be soft.
Serve Immediately: Carefully remove the Chocolate Lava Cakes from the oven. Allow them to cool for a minute before running a knife around the edge of each ramekin to loosen the cake. Invert each cake onto a serving plate. The center should be molten and gooey.
Optional Garnish: Dust the top of the Chocolate Lava Cake with cocoa powder or powdered sugar for a decorative touch.
Serve and Enjoy: Serve the Chocolate Lava Cakes immediately while the center is still warm and gooey. Garnish with a scoop of vanilla ice cream, a dollop of whipped cream, or fresh berries if desired.