How to Make It
Preheat the oven to 400°. Line a 9-by-13-inch metal baking pan with foil, leaving 2 inches of overhang on the long sides; lightly coat the foil with baking spray.
In a medium bowl, using an electric mixer, beat the butter with the sugar at medium speed until pale yellow and fluffy, 2 to 3 minutes. Scrape down the side of the bowl and beat in the egg, then beat in the almond meal, flour, oats and salt just until the dough comes together. Press the dough into the bottom of the prepared baking pan and refrigerate until chilled, about 30 minutes.
In a medium bowl, using an electric mixer, beat the butter with the brown sugar, salt and orange zest on medium speed until well combined. Add the oats and beat until incorporated. Press the oat topping into clumps.
Spread the jam evenly over the chilled crust and cover with the oat topping. Refrigerate for another 30 minutes.
Bake the bars for 15 minutes, until the topping just starts to brown. Reduce the oven temperature to 375°. Bake for about 25 minutes longer, until the center is just set and the topping is golden. Transfer the pan to a rack and let cool completely. Pull the long sides of the foil to remove the bar from the pan. Cut into bars and serve.