Yes, overbaking is the most common reason for chocolate lava cakes lacking a molten center. The cake cooks through completely, eliminating the desired liquid core.
Achieving the perfect molten center in a chocolate lava cake is a delicate balance. The goal is to cook the outer edges and sides of the cake just enough to set, while leaving the inside liquid and gooey. Overbaking occurs when the entire cake, including the center, reaches a temperature high enough to solidify. Several factors contribute to overbaking:
Oven Temperature: Ensure your oven is accurately calibrated. An oven that runs hotter than indicated will cook the cakes faster.
Baking Time: This is the most critical factor. Start checking for doneness a minute or two before the recipe's suggested time. The edges should be set, but the center should still appear slightly soft and wobbly.
Mold Size and Material: Different sized ramekins or molds will affect baking time. Dark-colored molds tend to bake faster than light-colored ones.
Recipe Accuracy: Follow the recipe precisely, especially regarding ingredient ratios. Too much flour can lead to a drier cake that cooks through more easily.
To test for doneness, gently shake the ramekin. The edges should be firm, and the center should jiggle slightly. You can also insert a toothpick into the edge of the cake; it should come out clean, while the center will remain gooey.
Chill the batter for at least 30 minutes before baking. This helps to solidify the outer layer faster in the oven, creating a greater temperature difference between the edge and the center, which promotes a molten core.