Preheat the oven to 350°F (180°C). Grease an 8 x 8–inch (20 x 20–cm) pan with butter or nonstick cooking spray and then line the pan with parchment paper, leaving an overhang on all sides. Grease the parchment with butter or nonstick cooking spray and then set it aside.
In a stand mixer fitted with the paddle attachment, cream together the butter and sugar on medium-high speed until fluffy, 3 to 4 minutes. Add the almond extract and salt and mix briefly. Add the all-purpose flour and almond flour and mix until the dough is crumbly.
230 g unsalted butter, 100 g granulated sugar, 1 teaspoon almond extract, ½ teaspoon fine sea salt, 240 g all-purpose flour, 95 g almond flour
Take half of the dough and press it into the prepared pan in an even layer using your fingertips. Mix the old-fashioned oats into the dough still in the mixing bowl, then place it in the refrigerator.
40 g old-fashioned oats
Bake the shortbread dough for 25 minutes, then remove the pan from the oven. Spread the jam evenly over the top of the partially baked shortbread, then add the peanut butter by spooning on dollops. Swirl/mix the two lightly with a spatula. Take out the reserved shortbread oat crumble and sprinkle it all over the top. Bake for an additional 20 to 25 minutes, until the bars are lightly browned on top. Let the bars cool completely, then cut into squares.
240 g your favorite jam, 100 g creamy peanut butter
Cover and store leftover bars in an airtight container at room temperature for 2 to 3 days.