i'm going to take minor exception to a point each from andy and goodweed.
- since it's a cake recipe, the original recipe is probably intended to be made with either all-purpose or cake flour, so there shouldn't be any need to adjust the ratio. if you've been using bread flour, that would certainly make the cake heavy and quite chewy, especially if you're beating it a lot. but, i'd try the original recipe with a.p. or cake flour first, before further adjusting the flour/liquid ratio.
- if you're chiefly interested in reducing
the heavyness, increasing
the fat content is not the usual road. adding another tablespoon or two of butter will almost certainly make it taste better, but it will also increase the heavyness.
- you didn't include the directions for the recipe, and how you proceed will make big differences in your final results. this looks like a typical two-bowl recipe, so here's the usual procedure:
1- cream the butter (not melted) and the sugar well
2- beat in the eggs at this point i'd follow goodweeds suggestion to use the yolks only, reserving the whites for later. add the vanilla.
3- thoroughly sift the dry ingredients. 3 times is best. the baking powder amount sounds small, so again goodweeds suggestion up increase the amount sounds about right. since you'll be beating the egg whites later, the first time around i'd stick with another 1/2 teaspoon, and if it's still too heavy use a whole teaspoon the next time.
4- alternate sifting in the dry ingredients with adding the milk.
5- whip up the whites and fold them in last. if you do this before, you'll end up beating a lot of the bubbles out.
one last observation is that if your oval
pan is the same 9" x 13" size as the rectangular
pan called for, the actual area will be a lot less, so the depth of the batter may be significantly higher. this will affect the baking time and heavyness as well. you may want to reduce the temperature by just a little, but increase the time a bit too.