One of my favorite projects that I remember doing in middle school was making (in class!!) a delicious pudding recipe to learn the different layers of the earth (crust, mantle, outer core, inner core). You can also consider revamping this idea for the different types of rocks as well (igneous, sedimentary, metamorphic).
I have seen a lot of different recipes for this experiment- so you can use whatever you have available. In middle school we simply made our ‘layers of the earth’ with different colored pudding and layers of graham crackers!
Here’s a more in depth recipe I found online:
1 sm. pkg. Cool Whip
1 can cherry pie filling
1 box Jello instant vanilla pudding
5 gummy worms