Multi-Grain Pancakes Stuffed with PB & Jelly

¾ c. white whole-wheat flour 3 T. cornmeal 3 T. old-fashioned rolled oats, finely ground ¼ c. peanut butter powder 2 T. sugar ½ t. baking soda ½ t. baking powder ¼ t. salt 1 2/3 c. low-fat buttermilk 1…