Preheat oven to 375°F.

Butter a 12-cup muffin tin. Combine flour, oats and salt the bowl of a food processor. Pulse to combine. Add butter and pulse until crumbly. Add ice water, 1 tablespoon at a time, pulsing until dough begins to hold together. On work surface, gather dough into a ball and divide into two pieces. Flatten into a disc, wrap and refrigerate for 45 minutes. When dough has chilled, roll to about ½-inch thick. Cut into circles using 3-inch cutter. Fit each round into the prepared muffin tin, pushing dough up the sides.

Combine brown sugar, flour, salt and cinnamon in medium bowl. Toss with melted butter. Set aside.

Attach vegetable sheet cutter attachment to KitchenAid® Stand Mixer. Insert food holder into center of one end of apple and secure onto attachment. Insert food skewer through apple, up to first mark. Attach Thin Blade to attachment. Position bowl under blade to catch apples. Turn Stand Mixer to Speed 2 and position blade against apple to process. Repeat with remaining apples.

Drizzle apple sheets with lemon juice to prevent browning. Cut apple sheets horizontally, then into 2- to 3-inch pieces. Arrange in circular pattern, beginning on the outside of dough and continuing to form flower pattern. Sprinkle with cinnamon sugar topping. Bake 20 to 25 minutes until beginning to brown. Let cool slightly before removing from pan.