There could be a few reasons why one side of a cake might be higher than the other when baking in an oven. Here are a few possible explanations:
Uneven heat distribution: Ovens may have variations in heat distribution, causing one side of the oven to be hotter than the other. This can lead to uneven baking and result in one side of the cake rising more than the other.
Oven rack position: The placement of the cake within the oven can also contribute to uneven baking. If the cake is not centered in the oven or if it is positioned closer to one side, the heat may be unevenly distributed, causing one side to rise more.
Pan placement: The position of the cake pan within the oven can affect how the cake rises. Placing the pan off-center or closer to one side of the oven can result in uneven heat exposure and cause one side of the cake to rise higher.
Uneven batter distribution: If the cake batter is not evenly spread in the pan before baking, it can result in uneven rising. The heavier side of the batter may cause that side of the cake to rise more while the lighter side remains lower.
Leaning oven: In some cases, the oven itself may not be level, which can lead to one side of the cake rising higher than the other. If the oven is tilted or leaning, gravity can cause the batter to distribute unevenly and result in uneven rising.
To minimize these issues, it is advisable to preheat the oven properly, place the cake in the center of the oven, ensure even batter distribution, and make sure the oven is level. Using an oven thermometer can also help monitor and adjust for any temperature variations.