• Preheat the oven to 350 °F (175 °C). Line an 8" x 8" pan with a full piece of parchment paper so that the entire pan is lined (and not just the bottom). Set aside.

For the crust and topping:

• In a large mixing bowl, stir together the dry ingredients (oat flour through salt). Stir in the melted butter until thoroughly combined.
  1 1/4 cups (115 grams) oat flour, 2 cups (180 grams) rolled oats, 1 tablespoon ground cinnamon, 1 cup (200 grams) brown sugar, 1/4 teaspoon salt, 3/4 cup + 2 tablespoons (196 grams) unsalted butter
• Pat half of the mixture (about 1 1/2 cups or 350 grams) firmly onto the bottom of the parchment-lined pan.
• Bake for 18 - 22 minutes or until lightly golden brown. The crust may bubble a little during baking.
• Let the crust cool for at least 10 minutes while preparing the filling. If the crust has any small bubbles, lightly press down the crust after it's cooled for a few minutes.

For the cheesecake layer:

• In a large mixing bowl using an electric hand mixer, beat the cream cheese and sugar at medium speed until light and fluffy. Add the vanilla, salt and egg and beat on low just until combined. Set aside while you prepare the apples.
  8 ounces (225 grams) cream cheese, 1/4 cup (50 grams) granulated sugar, 1 teaspoon vanilla extract, pinch salt, 1 large egg

For the apples:

• Mix everything together in a small bowl.
  2 cups (300 grams) apples, 1 tablespoon granulated sugar, 2 teaspoons ground cinnamon, 1/8 teaspoon ground nutmeg

To assemble:

• Spread the cheesecake batter evenly over the partially cooled crust. Distribute the apple filling over the top. Add walnut-sized pieces of the remaining oat mixture over the filling. Very lightly press down any parts of topping that are sticking out (to prevent burning). Bake for 30 - 35 minutes or until the filling is golden brown, firm and the middle doesn't jiggle when the pan is tapped.
• Remove from the oven and let cool completely. Refrigerate for at least 3 hours before serving. Cover and refrigerate any leftovers for up to 4 days.

For the caramel glaze:

• Melt the butter in a small saucepan over medium heat. Stir in the brown sugar and cream. Once well combined, stop stirring and let the mixture come to a full boil. Boil for 1 minute (without stirring) and then remove from the heat. Stir in the vanilla, salt, and gradually add the powdered sugar. Whisk until the powdered sugar is fully incorporated. Once the bars have cooled, cut into squares. Drizzle the glaze over the bars before serving.
  1/4 cup (56 grams) unsalted butter, 1/2 cup (100 grams) brown sugar, 1/3 cup (80 ml) whipping cream, 3/4 cup (86 grams) powdered sugar, 1 teaspoon vanilla extract, 1/8 - 1/4 tsp salt