What is the difference between self-rising flour and cake flour?
Cake flour is a low gluten flour. Gluten is a wheat protein that gives the bread structure and stiffness. Self-rising flour is just all-purpose flour with baking powder (or other leaveners) mixed in the flour. Your recipes was hard and spongy since you used a higher gluten flour and probably over-mixed (both act to toughen the pound cake). Spongy due to the leaveners in the self-rising flour. The leaveners create carbon dioxide which acts to create little bubbles in your batter... Yes, you are correct that the self-raising flour caused the problem. You can use all pupose flour but you need to be gentle with the mixing so you don't overly work the gluten - making the cake tougher. Here's a link to allrecipes.com There are 20 pound cake recipes... many are rated by the users so you can see what people thought about the recipes. http://allrecipes.com/Search/Recipes.asp...
My cake is undercooked?
Likely it's safe to eat. It may be undercooked, but it was likely still over the temp needed to kill any bacteria. Lava cakes are made that way on purpose. The outer shell is baked while the inside is still raw (and piping hot) If you followed the recipe to the letter and your cake came out like that you may have a thermostat that's out of calibration. Get an oven-safe thermometer and turn on your oven to 350 degrees and let it sit there for half an hour. Then read the thermometer. If you set for 350 and it's reading 325, then you know that you should either increase the cooking time or goose up the thermostat to 375. It's safer however to cook longer. Also invest in bamboo skewers. They're useful for testing a cake. Stick it in and pull it out. If it's clean (maybe a few crumbs sticking) then it's done. If it's got some uncooked batter, give it another 10 minutes and check again.
What is the difference in a pound cake and a bundt cake besides the pan they are cooked in?
No, a tube pan is removable at the bottom. A bundt pan is solid. Any cake baked in a bundt pan is a bundt cake. Its just a fluted pan with a hole in the middle. A pound cake is a specific type of cake that is dependent on the recipe, not the pan. A traditional pound cake is made with a pound of butter, a pound of flour, and a pound of sugar. You can find many wonderful pound cake recipes that give you the same dense, rich result. You can bake a pound cake in a bundt pan, or a loaf pan. It doesn't matter, both will be delicious.
Do you think cake box mixes taste bad? Which is best--dunken hines, pillsbury, or something else?
It depends on what I am making. And yes you can use pound cake mix/recipes for cupcakes. As for frosting, it is one of the easiest things to make. I have several recipes that start off with a boxed mix for a base and then I add to them. One of the easiest and best is: EASY POUND CAKE Ingredients 1 box yellow Duncan Hines Butter Recipe cake mix (MUST be this kind) 6 eggs 3/4 cup oil 8 oz sour cream 3/4 cup sugar 1 tsp of extract -- vanilla, lemon, orange, almond or strawberry (just pick the flavor you want your cake to be!) Glaze 3/4 cup powdered sugar 6 Tablespoons melted butter 1/2 teaspoon vanilla milk to thin as needed Preheat oven to 325 degrees Grease a bundt or angel food pan Mix all the ingredients until well blended and pour into greased pan. Bake for 1 hour or longer as needed. Mix together last 4 ingredients and spread on cake while hot. ***Variations: Can also be made using the Chocolate Butter Recipe Mix and vanilla, almond, mint or chocolate extract.