01 - Preheat the oven to 350°F. Line a 9x13-inch baking pan with parchment paper, leaving an overhang for easy removal.
02 - In a large bowl, combine flour, oats, granulated sugar, brown sugar, baking powder, and salt. Mix thoroughly until evenly distributed.
03 - Pour melted butter and vanilla extract into the dry mixture. Stir until the mixture becomes crumbly and evenly moistened throughout.
04 - Reserve 1 ½ cups of the crumb mixture for the topping. Press the remaining mixture firmly and evenly into the bottom of the prepared pan to create the crust.
05 - In a separate bowl, toss cherries with sugar, cornstarch, lemon juice, and almond extract. Mix until the cherries are evenly coated with the mixture.
06 - Spread the cherry mixture evenly over the pressed crust in the pan.
07 - Sprinkle the reserved crumble mixture evenly over the cherry layer, covering completely.
08 - Bake for 35 to 40 minutes, or until the top is golden brown and the cherry filling is bubbling around the edges.
09 - Allow the bars to cool completely in the pan. Lift out using the parchment paper overhang, then cut into bars and serve.