Preheat oven to 350F
To prepare 8in Square pan, I like to cut two wide strips of parchment paper to layer across the bottom of the pan. This would prove useful when extracting the bar after baking.
If Using a Food Processor: Pour in the flour, oats, sugar and almond flour with salt into the processor's bowl. Pulse for 30 seconds. Slowly drop in the butter cubes while pulsing. Then add in the vanilla. Process only until the dough looks like clumpy. Pour 2/3 of dough into a pan and press up the sides of the pan.
If Mixing by Hand: Pour flour, salt, oats, almond flour, and sugar into a bowl with cubes of butter. Work the butter into the flour mixture slowly until it forms clumps and some fine crumbs. Add in the vanilla extract and give it a mix. Pour 2/3 of the dough into a pan and press up the sides of the pan.
If the jam is too thick, dilute with a tablespoon of lemon juice BEFORE pouring into the dough. Pour the jam into the dough. Carefully ensure that jam is well distributed across the surface.
Sprinkle remaining dough over the jam with care. You want it to be well spread across the surface for a crumble effect.
Place the pan in the oven and bake the Peach Rhubarb Jam bar for 25 minutes. Take it out of the oven and allow it to cool down for at least an hour before attempting to slice.
Store in an airtight container in the refrigerator if there are leftover. It should hold up for about 2 days max.