01 - Preheat oven to 350°F. Line an 8x8-inch baking pan with parchment paper, leaving overhang to assist removal.
02 - In a large bowl, whisk flour, granulated sugar, matcha powder, and salt. Add cold cubed butter and work in with a pastry cutter or fingertips until mixture forms coarse crumbs.
03 - Press two-thirds of the matcha crumb mixture firmly and evenly into the base of the lined pan for a uniform crust. Reserve the remaining mixture for the topping.
04 - In a separate bowl, toss thinly sliced apples with sugar, lemon juice, and cinnamon until evenly coated. Arrange apple mixture in an even layer over the crust.
05 - Combine heavy cream, light brown sugar, unsalted butter, vanilla extract, and a pinch of salt in a small saucepan. Set over medium heat and stir until butter melts and mixture comes to a gentle boil. Simmer, stirring constantly, for 3 to 4 minutes until slightly thickened.
06 - Evenly drizzle the warm caramel sauce over the arranged apples.
07 - Sprinkle reserved matcha crumble mixture evenly over the caramel and apple layers.
08 - Transfer pan to oven and bake for 40 minutes, or until the topping is golden and caramel is bubbling at the edges.
09 - Remove from oven and allow bars to cool completely in the pan. Use parchment overhang to lift from the pan and cut into bars once set.