To make the pancakes:
In a large bowl, whisk together the flours, baking powder, baking soda, and salt. In a medium bowl, beat together the eggs, buttermilk, nonfat milk, honey, and vanilla.
Coat a large nonstick griddle or skillet with cooking spray and preheat over medium-low heat. Stir the wet ingredients into the dry ingredients, mixing only enough to combine them. The batter will be somewhat lumpy. Use a 1/4-cup measure to ladle the batter onto the griddle or skillet. Flip the pancakes when they are golden brown on the bottom and bubbles are forming on top, about 1-1/2 minutes. Cook the other side until golden brown, about another 1-1/2 minutes. Keep the pancakes warm in a 200°F oven as you finish cooking the remaining ones.
Ladle about 1/3 cup of the strawberry sauce onto each plate, place the pancakes on top, sprinkle with confectioners’ sugar, if using, and serve.