Hi, i'm making a cake for my friends birthday but I have a few questions before I start 1. One of the recipes I'm using calls for a 10 1/2x15 1/2-inch baking pan but I want to use my 9x9 round pan. I'm not sure if I should halve the recipe or cut it by 1/3 or what to make the appropriate adjustments. 2. I found this really cool orea dip recipe and want to use it as icing for my cake but I'm unsure whether it will be firm enough to use or not. It's almost the same as a few cream cheese frosting recipes I'v seen but it adds brown sugar. The recipes is essential cream cheese and powdered sugar beat together, then mixed with a a butter/brown sugar mixture that has been melted together. After I melt the butter and brown sugar together, can I refrigerate it for a little and then mix it with the cream cheese/powdered sugar to make a nice firm icing? 3. Also, do you think the amount of icing that this makes would be enough to cover a 3 layer cake? 1/2 cup butter 1/3 cup brown sugar 8 oz cream cheese 3/4 cup powdered sugar 1 tsp vanilla 3/4 cup crushed oreos 4. Lastly, I only have powdered vanilla extract, how do I use this in my icing & cake recipes instead of the liquid vanilla extract? Thanks!