Mix 2 cups flour, 1/2 cup sugar, 1 1/2 teaspoons baking powder, 1 teaspoon chia seeds and 1/2 teaspoon each baking soda and salt. In a separate bowl, whisk 3/4 cup each milk and vegetable oil, 2 eggs, 1 tablespoon lemon zest and 1 teaspoon vanilla; fold into the flour mixture. Line 12 muffin cups with paper liners; coat with cooking spray. Add the batter; bake at 350 degrees F until a toothpick comes out clean, 20 to 25 minutes.