Common Questions
Why is it called “impossible” cake?
Because it looks impossible that the layers switch places. During baking, the flan mixture is heavier and sinks while the cake batter rises, and once you invert it, the flan ends up on top with caramel glazing everything.
Do I have to use a water bath?
Yes, I strongly recommend it. The water bath keeps the oven heat gentle and even so the flan sets creamy instead of turning into sweet scrambled eggs along the edges.
Should I cover it with foil?
Usually, no. But if the top is getting too dark before the center is set, tent it loosely with foil for the remaining bake time. Do not seal it tight. Think “little foil hat,” not “tinfoil cocoon.”
My flan has bubbles or little holes. What happened?
Usually it is from overmixing or baking too hot. Blend just until smooth and keep the water bath truly hot. A few small bubbles are not the end of the world, especially under caramel.
How do I know it is done?
The cake should spring back lightly. For the toothpick test, aim near the outer edge of the pan where the cake layer is easiest to reach. A toothpick there should come out with a few moist crumbs. The flan will still have a gentle jiggle but should not slosh like a latte.
What if my caramel hardens in the pan?
Totally normal. It will melt again during baking. Just work quickly and tilt the pan right after pouring so it coats the bottom before it fully sets. If you can, let it creep a little up the sides too.
Can I make this without a Bundt pan?
You can use a 10-inch tube pan. A regular cake pan can work too, but flipping is riskier and the presentation is less dramatic. If you use a cake pan, line the bottom with parchment for extra insurance and keep the water bath.
Why won’t it release from the pan?
Most often it needs more chilling time, or the caramel cooled too pale. Chill at least 6 hours, then dip the pan in warm water for 15 to 20 seconds and run a thin knife around the edges before inverting.
