Yes, there can be a difference in taste between cakes made with instant pudding and those made with box mixes plus dry instant pudding mix. The primary reason for this difference lies in the ingredients and their proportions.
Box Mixes: Cake mixes are pre-packaged dry mixes that typically contain flour, sugar, leavening agents, and various flavorings. They are designed to be quick and convenient, requiring minimal effort to prepare. However, they may not always have the same richness and depth of flavor as homemade cakes.
Dry Instant Pudding Mix: Instant pudding mix is a powder that contains starch, flavorings, and sometimes other additives. When used in cakes, it can add moisture, texture, and flavor to the final product. The pudding mix can also enhance the cake's richness and make it more tender and moist.
When you use a box mix and add dry instant pudding mix, you are essentially adding additional flavorings and moisture to the cake, which can result in a slightly different taste compared to a cake made solely with instant pudding.
In contrast, using only instant pudding in a cake recipe might produce a more pudding-like texture and a more pronounced pudding flavor. On the other hand, combining the two may strike a balance between the convenience of the box mix and the enhanced flavor and texture provided by the pudding mix.
Ultimately, the taste difference may not be overly significant, but it can still be noticeable depending on personal preferences and the specific brands or flavors of cake mix and pudding mix used. Some people may prefer the convenience and simplicity of a cake made with just a box mix, while others may enjoy the added depth of flavor and texture that comes from incorporating the dry instant pudding mix.