Add yeast and coconut palm sugar in warm almond milk in a small bowl. The milk should be no more than 100 degrees F (40 degrees C). Let stand for 15-20 minutes until the yeast softens and begins to foam.
Whisk the egg whites, melted coconut oil, and lavender extract into the yeast mixture until evenly blended; set aside. Stir together the flour and salt in a separate large bowl, then make a hole in the center of the batter. Pour the egg mixture into the hole, then stir in the flour mixture until a soft dough forms. Cover with plastic wrap or a cloth and let rise in a warm humid place until doubled in volume, about 30-40 minutes. Gently mix in the keto brown sugar and almond slivers until incorporated.
Preheat a waffle iron according to the manufacturer's instructions. Lightly grease the iron with oil.
Place a baseball-size ball of dough on the preheated waffle iron. Cook the waffles until golden and crisp, about 1-2 minutes. don't cook for longer or the waffles will burn. Repeat with remaining dough. Allow waffles to cool for 2 to 3 minutes before serving. Serve with berries, extra and/or topping of choice.