Follow these simple steps to create your Chocolate Lava Cake:

1. Preheat the Oven: Begin by preheating your oven to 425°F (220°C). This high temperature ensures that the outside of the cake sets while the inside remains gooey.

2. Prepare Ramekins: Grease four ramekins with cooking spray or butter. This prevents the cake from sticking and allows easy removal after baking.

3. Melt Chocolate and Butter: In a microwave-safe bowl, combine the semi-sweet chocolate chips and unsalted butter. Heat in the microwave in 30-second intervals, stirring between each interval until melted and smooth.

4. Combine Sugar: Add powdered sugar to the melted chocolate and butter mixture. Stir until you have a smooth combination.

5. Add Eggs: In a separate bowl, whisk together the eggs, egg yolks, and vanilla extract. Gradually add this to the chocolate mixture, stirring continuously until well incorporated.

6. Mix in Flour: Gently fold in the all-purpose flour until just combined. Be careful not to overmix; the batter should remain slightly lumpy.

7. Fill Ramekins: Evenly distribute the batter into the prepared ramekins, filling each about ¾ full for the perfect lava effect.

8. Bake: Place the ramekins on a baking tray and bake in the preheated oven for 12-15 minutes. The edges should be firm, while the center remains slightly jiggly.

9. Cool Slightly: Allow the cakes to cool for about 5 minutes after taking them out of the oven. This cooling period will help firm up the outer layer, making it easier to remove from the ramekins.

10. Serve: Carefully run a knife around the edges of each cake, then invert onto individual plates. Serve immediately for the best lava effect!