Why more developmentally appropriate? Well you can make your dough appropriate for the right age- oatmeal play dough for older babies/toddlers, a soft cooked dough for young preschoolers, a firmer play dough for older preschoolers, and a clay you can make and dry sculptures out of for older kids. You figure out whats right for you and go for it.
Here is the recipe I used today-
1 cup of flour
1 T. vegetable oil
1 cup water
2 t. cream of tartar
1. mix the food coloring into the water
2. heat all the ingredients over low heat until the mixture forms a ball
3. knead when cool
I didn't use food coloring- I am out of food coloring and find it works better without it sometimes. It doesn't matter if it gets mixed up like it does if you have several colors.