There are alot of recipes for sturdy cakes here on CC. One of my favorites is Sharon Zambito's cake recipe. I don't know how to link it so here is the recipe. It is a very thick batter. I usually fill my tins about 2/3 to 3/4 full then I can level them right in the pan with a long serrated knife.
1 box cake mix (Betty Crocker works well)
1/2 cup water
1/3 cup veg, oil
1 whole egg
3 egg whites
1 cup sour cream
1 small box flavored instant pudding to match cake flavor
1 tsp extract vanilla, almond etc. to match.
If making chocolate cake, add 1 extra TBSP veg oil.
I bake at 325 degrees.
Hope this helps