Follow these step-by-step instructions to create perfect Mini Chocolate Lava Cakes:

1. Preheat Oven: Begin by preheating your oven to 425°F (220°C). This high temperature is crucial for achieving that gooey center.

1. Prepare Ramekins: Grease four 6-ounce ramekins with butter, then dust with flour to prevent sticking. Set aside.

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

1. Whisk Eggs: In a separate mixing bowl, whisk together the eggs and egg yolks until well combined. Gradually add the granulated sugar while whisking until it becomes light and frothy.

1. Combine Mixtures: Pour the melted chocolate mixture into the egg mixture. Add vanilla extract and mix until incorporated.

1. Add Flour and Salt: Gently fold in the flour and salt, ensuring everything is just combined. Be careful not to overmix; a few lumps are okay.

1. Fill Ramekins: Evenly distribute the batter among the greased ramekins, filling them about ¾ full.

1. Bake: Place the ramekins on a baking sheet and bake in the preheated oven for 12-15 minutes. The edges should look firm while the centers remain soft.

1. Cool Briefly: Remove from the oven and let the cakes cool in the ramekins for 5 minutes.

1. Invert and Serve: Carefully run a knife around the edges of each cake and invert onto a plate. Dust with powdered sugar if desired, and prepare for smiles!