How to make Silvanas, the "Filipino Dacquoise"

Silvanas, alternatively spelled as sylvanas or sylvannas, is a Filipino frozen cookie consisting of a layer of buttercream sandwiched between two cashew-meringue wafers coated with cookie crumbs. Silvanas are the cookie versions of the Sans rival, a Filipino cake made from similar ingredients. You may find some cool small kitchen tools that you can use by clicking the link below: https://amzn.to/3h2xJGh   / maysflair   https://www.instagram.com/mays_flair/...   / maybakescakes   Ingredients: Wafer: 2/3 cup Egg Whites 8 tbsp Cornstarch 1 cup ground Cashew Nuts 1/2 tsp Cream of Tartar 2/3 cup Granulated Sugar Buttercream: 1 cup Granulated Sugar 6 pcs Egg Yolks 2 cups Unsalted Butter 3 tsp Vanilla Paste *Digestive or Bourbon biscuit crumbs to coat the Sylvanas