Chocolate Lava Cakes

This recipe is adapted from a similar one in Cuisine at Home, a magazine I truly love. Ground rule for these decadent little cakes: use really good ingredients. That means quality chocolate, good cocoa powder, and real pure vanilla extract and butter. I will hunt you down and kick your butt if you defile this recipe with generic butter-flavor shortening, imitation vanilla, or store-brand chocolate chips. So don't do it.

Ingredients:
For 4 to 6 individual cakes:
8 oz semi-sweet chocolate, or about 1 1/3 C chocolate chips
1 1/2 sticks unsalted butter
4 eggs
1/2 C sugar
1/4 C flour
1 Tbsp cocoa
2 tsp vanilla
1/2 tsp kosher salt

For 1 single, decadent cake for your private chocolate indulgence:
2 oz chocolate, or 1/3 C choc chips
3 Tbsp unsalted butter
1 egg
2 Tbsp sugar
1 Tbsp flour
1 scant tsp cocoa
1/2 tsp vanilla
1/8 tsp kosher salt

Steps:

1. Find the needed number of ramekins, small oven-safe bowls, or single-serving baking dishes. They should hold between 6 oz and a cup. You can use bigger ones, but the baking time will become more experimental; it's up to you. Spray your baking vessels well with non-stick spray. Preheat the oven to 375 F.
2. If using block chocolate, chop it into small pieces. Place the chocolate and butter in a microwave-safe bowl and melt in the microwave, checking and stirring in 30 second increments until melted and blended smooth. Don't scorch!
3. Meanwhile, beat the egg and sugar together in a bowl. I highly recommend an electric hand mixer for this. Keep beating until the color turns from bright to pale yellow and the consistency starts to thicken like lightly whipped cream. By hand this will take 5 minutes or longer. The beaten egg is the only leavening in this recipe, so don't wimp out on this step!
   
4. Add flour, salt, cocoa, and vanilla to the egg mixture, and beat even more until it's well combined.
5. Add the chocolate/butter mixture and beat again for several more minutes. The batter will be rather thick.
6. Divide batter evenly among your baking vessels, place the vessels on a baking sheet, and bake 15-20 minutes (small sizes less, larger sizes longer). Check frequently after the first 15 minutes. Don't overbake! The cakes will be done when they are puffed and the edges are mostly dry, but the centers will still appear sunken and somewhat wet. They should still jiggle slightly in the middle when shaken.
7. Let the cakes rest several minutes in their baking dishes after removing from the oven. Then, while they are still warm, run a dull knife around the inside of the dishes to loosen the cakes. Place a plate over the top of each baking dish and quickly invert. The cakes should unmold easily onto the plates. No topping is needed, but whipped cream, good vanilla ice cream, or macerated berries make a delicious extra. Break into one cake with a fork; if you find warm gooey fudge puddling out of the center, you will know the cakes are just right.

Sneaky make-ahead tip: The batter may be made several hours in advance, portioned into the baking dishes, tightly covered and refrigerated until ready to bake. Add an extra minute or so to the baking time, and put the cakes in the oven as you sit down to dinner. You'll have warm-from-the oven dessert ready 20 minutes later.