Line a full sheet pan with parchment paper and brush it with melted butter. Dust the paper with confectioners' sugar and place 2 sheets of phyllo dough side by side on the pan.
Brush the phyllo sheets with butter and dust with confectioners' sugar. Place a second phyllo sheet on top of each of the first sheets, brush them with butter and dust with confectioners' sugar. Continue until there are two stacks of phyllo dough, each four layers high.
Using a pastry wheel, cut each stack of phyllo into four columns and four rows, to create 16 small rectangular stacks from each large stack.
Cover the stacks with parchment paper and another sheet pan (bottom down) to keep the phyllo flat. Bake at 325°F. until brown, approximately 15 minutes. Remove from the oven and cool completely.