I made the Louisa Cake last night and, while the flavor was delicious, my cake turned out very moist and dense. The description says it should be...

A most wonderful cake, indeed, Nancy! It's one of those cakes you make over and over and over again.

This is a moist and dense cake for sure. This is not airy - but it does have a light feel to it due to the ricotta and apple. Very high in protein (10 grams). It's light like flan is light.

Cream the butter + sugar for at least 5 minutes until lite and airy. Don't over mix this cake. After adding the dry ingredients, mix just until combined on low speed. After the apples are added, then mix the cake with a spatula.

Is it right to bake this cake at 400 degree?

One more thing. You may also want to experiment with beating the egg whites separately until it forms soft peak and, as the last step, gently fold it into the batter. Doing this usually makes a cake lighter.

Based on the ingredients for this cake, I would myself know before making the cake that it would not necessarily be light and airy, but more like a butter or pound cake. This being said, however, other things do contribute to the lightness of a cake. First, you really want to make sure you beat the sugar and butter until it is indeed very creamy and fluffy, for lack of a better expression. Second, you want to make sure the flour is well incorporated into batter, but you don't want to overbeat the batter because this can result in a heavier cake. However, I think that whoever makes this cake will see it is not necesarily "light and airy" but more along the line of what you described, that is very moist and dense. I have yet to make it myself, I admit; but I don't think I am wrong. D) Also the picture of the cake seems to show a cake that is more "moist and dense" than "light and airy." Nothing wrong with that though.