Whether you are baking a cake, brownies or other types of sweet treats, making substitutions while baking can be tricky. But substituting one cake pan for another should never be as complex as substituting baking soda for baking powder. In fact, using different pan sizes requires just a few minor modifications in baking time and an occasional adjustment in oven temperature.
Measure the dimensions of your pan from inside edge to inside edge. Measure the pan's depth by placing a ruler straight up from the inside bottom of the pan. Avoid tilting the ruler, even if the cake pan has a slanted shape.
Figure out the volume of cake batter each pan size holds. If you do not have a pan dimension chart available -- such as the one provided by the Joy of Baking website --, pour 1-cup servings of water into the pan until it is filled.
Choose a pan that holds the same amount of volume. For example, if your recipe calls for a round pan with 8-inch by 2-inch dimensions, substitute a square pan with 8-inch by 8-inch by 1.5-inch dimensions. Although different shapes and sizes, both pans hold 6 cups of batter. In this case, use the same baking time and oven temperature called for in the recipe.
Choose a pan with a similar volume capacity if a pan with the exact same volume is unavailable. Using a smaller pan results in a thicker layer of cake batter, while using a larger pan results in a thinner layer of batter.
Use the same oven temperature as called for in the recipe. Although you are using a different pan size, it's not necessary to change the baking temperature. Adjusting only the baking time should be sufficient to ensure successful results.
Adjust the oven temperature only if you are using a dark nonstick pan or a glass baking dish. Since these pans tend to result in quicker browning of the batter, reducing the oven temperature by 25 degrees F can prevent over-baking.
Adjust your baking time based on the new cake pan size. As a general rule, pans with a volume of 6 cups should bake for 30 to 35 minutes and pans with a volume of 8 cups should bake for 25 to 30 minutes. Adjust your baking time by approximately five-minute increments for other pan sizes.
Adjust the oven temperature if the cake begins to bake unevenly or brown too quickly at the edges. In this case, simply reduce the oven temperature by 25 degrees F and keep a close eye on the cake.
Watch the cake carefully as it nears the end of its baking time. Once the edges of the cake start to pull away from the edges of the pan, remove it from the oven.
Check the cake for doneness by inserting a clean toothpick into the center of the cake. If it comes out clean with just a few crumbs, the cake is done. The center of the cake should also bounce back after gently tapping it, but no fingerprints should be left in the surface.