Making the Bars

• Preheat the oven to 300°F (149°C). Spray the sides and bottom of an 8x8 inch square baking pan with cooking spray, then set aside.
• In a stand mixer fitted with paddle attachment, cream softened butter with vanilla and confectioner’s sugar on low speed until combined. Gradually add the flour, oat flour, cornstarch, and salt, mixing until you have a nice looking dough, about 3 minutes. Press the mixture into your square baking pan and bake for 15 minutes.
• Mix the sliced apples, flour, brown sugar, cinnamon, ginger, cloves, and nutmeg together in a large bowl until all of the apples are evenly coated. Set aside.
• Stir the melted butter, oats, brown sugar, cinnamon, and flour together in a medium bowl. Mix until the mixture resembles coarse crumbs. Set aside.
• Turn the oven up to 350°F to preheat. Arrange apple mixture on top of shortbread crust, pressing them down. Sprinkle the apple layer with streusel, pressing down lightly. Bake for 30 minutes.
• Remove from oven, cool for 20 minutes, then chill in fridge for a few hours.
• While the bars are chilling, place water in a medium saucepan, pour the sugar into the center, cover, and bring to a boil. Once boiling, uncover and continue boiling until syrup registers 300 degrees on a digital thermometer. Reduce heat and continue cooking until syrup is deep amber.
• While waiting for the caramel, bring the cream and salt to a simmer in a small saucepan. Remove the sugar syrup from heat and carefully pour in half of the hot cream, whisking continuously until smooth.
• Cool and refrigerate the caramel. Drizzle salted caramel sauce on top of each bar when serving.