Preheat oven to 350 degrees F.
On a piece of kitchen parchment, trace the bottom of your serving bowl that will be in the center of your biscuit wreath. Turn the parchment over and use to line your baking sheet. Set aside.
In a bowl, stir to combine sugar, pumpkin pie spice, and cinnamon; set aside.
Open can of biscuits and separate into individual biscuits.
Sprinkle a rolling surface with some of the sugar-spice mixture. One at a time, press each biscuit into the bowl of sugar-spice mixture. Roll each biscuit on sugared surface to a 5-inch diameter. Using 2-inch and/or 3-inch leaf cutters, cut leaf shapes for your wreath; reserve dough scraps. Position leaves overlapping around the circle drawn on parchment. Set aside.
Lightly beat egg with 1 tablespoon of water. Using a pastry brush, paint egg wash between the leaves where they overlap.
Re-roll extra dough to cut out single leaf shapes or to make mini individual wreaths.
Bake in preheated oven for 14 to 17 minutes. Remove from oven and cool completely before moving.
While wreath is baking, stir together sifted powdered sugar and maple syrup until smooth. Cover and set aside.
Once wreath has cooled, use a clean paint brush to apply glaze to leaves - painting every other leaf so that there is separation.