We wanted a sugary coating that would stick to the cake rather than fuse the cake to the pan.
Recently we ran across an idea for giving Bundt cakes a crackly, sugary crust while they bake, saving the need to make a frosting or glaze. The idea is to coat the pan with sugar before adding the batter, so that in the heat of the oven it melts into a lacy crust. The challenge would be to create a sugary coating that would stick to the cake rather than fuse the cake to the pan. First we tried coating the pan with a hefty amount of vegetable oil spray before dusting it with granulated sugar. Unfortunately the spray’s coating was too thin, and the cakes almost always stuck. Next we tried brushing the pan with melted butter and then dusting it with sugar. These cakes released easily, but there was no crunchy coating. Why? The sugar had dissolved in the water in the butter (butter is nearly 20 percent water).
In the end, we landed on brushing the pan with 1 tablespoon vegetable oil before coating it with 1/3 cup of sugar. It provided a thick coating of pure fat that was easy to brush on and guaranteed that the cake released with ease. What’s more, the sugar turned into just the lacy, sweet coating on the cake that we were looking for.