This is a gluten free recipe.
Some sour creams have fillers and could have gluten. Be sure you buy PURE sour cream (Breakstone and Daisy are good).
Make sure that creamed corn is thickened with cornstarch, not modified food starch.
Some commercial brands of baking powder have gluten, so read the label and make sure that they have no gluten.
Makes a 10-inch round pan - double it for a 9 x 13-inch pan.