In a large mixing bowl combine flour, granulated sugar, baking powder, and salt
In a separate bowl, combine milk, oil, melted butter, lemon juice, poppy seeds, and lemon zest
Mix well; add all at once to flour mixture
Gently mix until just combined
Beat egg whites until soft peaks form; gently fold into batter
Let batter rest 5 minutes
Pour by ¼ c. onto prepared skillet
Wait until bubbles form on the surface and pop; then flip pancakes until golden brown on both sides
For glaze, combine powdered sugar, lemon juice, and poppy seeds and mix until smooth
Pour over pancakes as desired