Preheat your oven to 425 degrees F. Using softened butter, grease the inside of each ramekin thoroughly, making sure to cover the bottom and all the way up the sides. Add a small pinch of flour to each ramekin, tilt and rotate to coat the inside, then tap out any excess. Set the ramekins on a rimmed baking sheet.

Melt the chocolate and 6 tablespoons of butter together. You can do this in a saucepan over very low heat, stirring constantly, or in a microwave-safe bowl in 30-second bursts, stirring between each. Once fully melted and smooth, set aside to cool for 2 minutes.

In a medium bowl, whisk together the eggs, egg yolks, and granulated sugar until the mixture turns slightly pale and thickens a bit, about 1 minute of good whisking. Whisk in the pumpkin puree, pumpkin pie spice, salt, and vanilla extract.

Pour the melted chocolate mixture into the egg mixture and whisk until fully combined. Add the 1/4 cup of flour and fold gently with a rubber spatula just until no streaks of flour remain. Do not over-mix.

Divide the batter evenly among the 4 prepared ramekins. Each ramekin should be about three-quarters full.

Bake for exactly 12 minutes. The edges should look fully set and slightly pulled away from the ramekin walls, but the center should still jiggle when you gently shake the pan. If the tops look completely firm and dry, they have gone a minute too long.

Remove from the oven and let the cakes sit in the ramekins for exactly 1 minute. Run a thin knife around the inside edge of each ramekin to loosen. Place a dessert plate upside down on top of the ramekin, then carefully flip both together. Hold for 10 seconds, then lift the ramekin straight up. The cake should release cleanly.

Serve immediately with a scoop of vanilla ice cream on the side. The molten center will begin to set quickly, so do not let them sit.