Preheat oven to 350 F. Line an 8x8 metal baking pan with parchment paper and lightly grease with nonstick spray.
In a medium mixing bowl, whisk together the almond flour, oats, brown sugar, cinnamon and salt. Use a fork to stir in the melted butter. Mix until clumps being to form.
Transfer 2/3 of the mixture to the prepared baking pan. Use your fingers or the back of a spoon or measuring cup to press the mixture into the bottom of the pan. Set remaining crumble aside (it will be the topping).
Spread the jam evenly over the crust layer.
Add the slivered almonds to the remaining crumble mixture and sprinkle the mixture over the jam layer.
Bake at 350 F for 30 minutes or until the filling is bubbling at the edges and the crumble is lightly browned. Cool bars completely at room temperature, then transfer to the refrigerator to chill for 20 minutes before serving.
Notes
Store bars in an airtight container in the fridge for up to 5 days.