In a 12" x 17" pan? Don't do it, that will overflow. You can barely bake two boxes per sheet, it's nearly too much. As for the timing for two boxes, it's about 35-45 minutes at 325-350 degrees.
Poke some holes in it with a fork and wrap in foil bake at 300 degrees for 1 to 1 1/2 hours.In the microwave no foil and cook on high for 8 to 10 minutes.
Well. If you made the half cake from a box then do and estimate for about half the time for a whole cake. I LOVE baking.
The boxes I checked said one box would make a 13x9, so you will need about 1 1/2 boxes for a 12x18. Assuming the pan is deep enough you could use two boxes for a one layer 12x18 or you may want to make a two layer cake using 1 1/2 box per layer.
You can bake two batches of cookies at the same time if you have enough cookie sheets and oven space. If you do not have enough space, you can bake half of them, and then bake the second half immediately after.
Figure on a half-sheet pan; around 18" by 13". Or you could use two quarter-sheet pans (9x13) and combine them; this may work better in a home oven. Quarter-sheets are convenient, because they're the "standard size" for home pans, and they're the size pan that boxes of cake mix are designed for.
Okay so here you go! There are approximately 4-5 cups of batter in one cake mix. For a half of a sheet cake, I use 3 cake mixes, so for a full, that's 6. You will have a little bit left over too.
It will probably take 1-1/2 boxes. Fill the pan roughly half full & use the rest for cupcakes.
1 cake
It varies greatly. Some are small, some are larger. Typically, most are about 9 inches by 13 inches, and 2 inches deep. Any variation within 2 or 3 inches of this is considered about "average".
Physical changes are ones which do not affect the chemical composition of a substance. For instance, if you cut a cake in half, that is a physical change. Nothing has changed except the shape, weight, and size of the cake. When you bake the cake batter, however, you are causing a chemical change. The batter changes into a cake; when you cut the cake, it doesn't change into anything.
If Jackie has 1/3 of half a cake then he had half of half a cake. This is a math problem.
Mrs. George baked a chocolate cake, left it on the counter to cool, and then later applied home-made chocolate icing. The bakery offered an assortment of cake sizes, including full-sheet, half-sheet, and one, two, and three tiered sizes. Almost all birthday parties feature the traditional cake and ice cream; for many people, the cakes presented on their birthdays is a pleasant memory. To bake a cake, most people follow a family recipe, or use a pre-packaged cake mix. A layered cake has tiers of cake with icing in between each layer, plus icing on the top and the sides. Bakers make cakes for all kinds of occasions besides birthdays, including: reunions, retirements, graduations, Sweet 16 events, and other parties.