Gluten Free Bulk Pancake Mix

I have been trying to simply some things at home as well as teach more independence for the girls.  I now have my oldest making pancakes using this bulk mix.  This mix can be prepared in advance and makes about 4 batches.  Each batch makes about 8-10 pancakes.
Ingredients 

• 2 cups tapioca/arrowroot starch
• 2 1/4 cups sorghum flour
• 1/2 cup buckwheat flour
• 1 cup coconut flour
• 1 cup chickpea flour
• 4 tablespoons baking powder
• 1 teaspoon sea salt

To Make Pancakes

• 2 cups mix
• 1 1/2-2 cups milk
• 2 eggs
• 1 teaspoon vanilla (optional)
• chopped apple (optional)
• 1 teaspoon cinnamon (optional)