Too often, baking recipes call for specific pan sizes a home cook simply doesn’t have. What to do when you want to make a recipe intended for a loaf pan, but only have an 8-inch square? And what about when you want to convert a 13-by-9-inch cake into muffins? We wanted some simple guidelines to help adjust a few crucial recipes for various pans.
So we selected the most popular and basic baked goods—quick bread, pound cake, layer cake and brownies. We baked the same recipe in a variety of appropriate pans, including a 9-by-5-inch loaf pan, a 9-inch round, an 8-inch square, a muffin pan and mini-loaf pans. We monitored doneness to calculate variations in timing from pan to pan, and to keep our testing focused, we only adjusted times, not temperature.
Some conversions were relatively straightforward. A layer cake baked in an 8-inch round rather than the called-for 9-inch round required only a minute longer in the oven and resulted in a slightly taller cake. Brownies were similarly simple, taking five minutes less in a 9-inch square than in an 8-inch. A double batch baked in a 13-by-9-inch pan needed five minutes longer, but didn’t suffer any other discernable differences.
Conversions for quick bread and pound cake proved trickier. The change in surface area from a 9-by-5-inch loaf pan to an 8-by-4-inch pan was more drastic, affecting not only bake time, but also appearance. In the smaller of the two pans, quick bread took longer to bake, browned more deeply and were more domed. Pound cakes also took longer in the 8-by-4-inch loaf pan.
Though converting from one pan to another will always involve some guesswork, we did extract a few guiding principles from our testing. First, baking in a smaller pan than called for means the baked good has less surface area and will generally take longer to bake. Likewise, batter will cook faster in a larger pan.
Second, if you’re using a different pan, adjust your expectations. Not only will the timing change, but the browning and overall shape of the baked good may vary, as well. Cakes and bread baked in mini-loaf pans finished quickly and didn’t develop the golden brown hue we prefer (increasing oven temperature may help).
Finally, a note on pan color and material. In general, dark pans absorb and conduct hear more quickly than light-colored pan, but we didn't observe substantial differences in our testing. We did, however, see a pronounced difference in glass versus metal. Quick breads and cakes didn't brown well in glass and had tacky bottoms and sides. If a recipe calls for a baking pan, we advise against using a glass dish.