In large bowl, whisk flour with cornmeal, sugar, baking powder, chili powder and salt. In another bowl, whisk egg with milk and 2 tbsp (30 mL) oil. Stir wet ingredients into dry ingredients until just moistened (it’s fine if batter is still lumpy). Fold in corn, ham and cheese. Let batter stand for 15 min., or cover and refrigerate up to 24 hr.
Preheat large, non-stick skillet or griddle over medium heat. Brush skillet with some of remaining oil. In batches, pour 1/4 cup (60 mL) batter per pancake into skillet, spacing out pancakes to allow spreading. Cook 2 min., or until bubbles form on surface. Flip and cook 1 to 2 min. more, until bottom is golden. Wipe skillet between batches and brush with more oil as needed.
Serve pancakes with sour cream and sliced green onions or with maple syrup.
Store cooked pancakes between layers of parchment paper, in an airtight container; freeze up to 1 month. Arrange in single layer on baking sheet to re-warm in oven.