Preheat the oven to 350 F (177 C). Line an 9 x 9 pan with parchment paper along the bottom and two sides.If using fresh peaches, remove the seed and slice the peach into 8 segments. Dice the segments into ½ sized pieces. If you would like to remove the skin, make sure to peel the peaches prior to dicing them. If using frozen peaches, thaw the peaches until they are cool, no longer frozen to the touch before using in the recipe. Add the diced peaches, sugar, light brown sugar, cornstarch, vanilla extract and salt to a large mixing bowl. Toss the ingredients together until the peaches are fully coated. Set aside while making the shortbread crust and crumble topping.
3 cups diced peaches , ¼ cup (50 g) granulated sugar, ¼ cup (50 g) light brown sugar, 1 tablespoon cornstarch, 2 teaspoons (10 ml) vanilla extract , ¼ teaspoon salt
Make the butter cookie crust and crumb topping by combining the flour, sugar, light brown sugar, baking powder and salt together in a food processor. Pulse 2 -3 times to combine the ingredients. Pulse in cubes of cold butter until the mixture resembles a crumble texture. Finally pulse in the egg yolk and vanilla extract until the mixture starts to clump together.
2¼ cups (270 g) all purpose flour, ½ cup (100 g) granulated sugar, ¼ cup (50 g) light brown sugar, ½ teaspoon baking powder, ½ teaspoon salt , ¾ cup (170 g) cold cubed butter, 1 large egg yolk, 1 teaspoon vanilla extract
Evenly press half of the shortbread mixture into the prepared pan. Using a slotted spoon, transfer the peach filling onto the shortbread crust. Top the peach filling with the remaining crumble mixture. Make sure to cover as much of the peach filling as much as possible, but spots of exposed filling is fine.
Bake the fresh peach bars for 35 - 45 minutes or until the crust is a nice golden brown with edges of the crust pulling slightly away from the sides of the pan. The peach filling will thicken and bubble.
Cool the peach crumble bars in the pan for 1 hour. If the bars are too soft to easily transfer from the pan after 1 hour at room temperature, transfer to the fridge to set for another hour. Once the bars are set, top with powdered sugar, vanilla glaze or enjoy as is.