Preheat oven to 350 degrees F.
Into a large bowl, sift together the flour and sugar.
In a small bowl, mix the egg whites and butter together. Slowly add to dry ingredients. Mix so all lumps are removed.
Using a silicone mat, lay out a stencil (whatever shape you desire), and spread batter with a pallet knife so the batter is the same thickness as the stencil.
Place in the freezer for 3 to 4 minutes and remove. Run a knife around the inside edge of the stencil, making sure not to alter the shape of the biscuit.
Bake on a sheet pan for 4 to 6 minutes until lightly brown around the edges.
Recipe courtesy of David Marcelli