This is the one I make every Sunday.
In a bowl mix until crumbly:
2-1/2 cups flour (you can sub 1 cup of rolled oats)
3/4 cup sugar
3/4 cup brown sugar
3/4 cup melted butter, coconut oil, or 1 cup veg oil
Set aside 1 cup of mix
Using the rest of the mixture add:
1 cup buttermilk (or 1T vinegar to 1 cup of milk)
1tsp baking soda
1tsp baking powder
Mix and pour into 9x13 pan. Sprinkle reserved crumbles on top, bake at 350 for 30 minutes.
I change it up by adding rolled oats and oumpkin pie spices align with the cinnamon.