Preparation Steps:

• Preheat your oven to 350°F (175°C). Grease or line your 9x13-inch baking pan with parchment paper for easy removal.
• In a large mixing bowl, combine 2 cups of all-purpose flour, ¾ cup of granulated sugar, ½ teaspoon of kosher salt, and 1 teaspoon of baking powder. Whisk together until well blended.
• Add ¾ cup of chilled unsalted butter pieces to the flour mixture. Using a pastry cutter or your fingers, mix until the mixture resembles coarse crumbs.
• Pour in 3 tablespoons of milk and 1 teaspoon of almond extract. Stir until just combined, ensuring not to overmix. This will be your base layer.
• Press the mixture firmly into the bottom of the prepared baking pan, creating an even layer.
• Spread 1-1/2 cups of your favorite jam or fruit preserves over the crust layer. Make sure to distribute it evenly for a balanced flavor in every bite.
• In a separate bowl, mix 1-½ cups of all-purpose flour, ½ cup of light brown sugar, ¾ cup of granulated sugar, ½ teaspoon of kosher salt, 1 teaspoon of baking powder, 1 teaspoon of ground cinnamon, and ½ teaspoon of ground cardamom (if using). Stir in 1 cup of rolled oats.
• Cut in the remaining ¾ cup of chilled unsalted butter until the mixture is crumbly.
• Sprinkle the oat crumble mixture generously over the jam layer, covering it completely.
• Bake in your preheated oven for 30-35 minutes, or until the top is golden brown and the jam is bubbly.
• Allow the bars to cool in the pan on a wire rack. Once cooled, dust with powdered sugar if desired, then cut into squares or bars.