Preheat the oven to 350°F and prepare two 8x8 baking dishes by lining them with aluminum foil. then place a larger piece of parchment paper on top and leave an overhang of the parchment paper so you can easily pull the bars out of the pan when they are cooled.

In a large mixing bowl, combine the flour, baking soda and salt. Once combined, add the oats and brown sugars.

Use your fingertips to combine the mixture until there are no clumps.

Add the butter and use your fingertips to crumble it into the mixture. Continue to work the dough until there are no chunks of butter and the mixture looks like sand. 

Add 2 cups of mix to the baking pans and press the dough into even layers as the base. 

In a separate bowl, combine the raspberry jam, strawberry jam, lemon zest, and lemon juice. 

Divide the jam filling evenly among the two baking dishes and spread it in an even layer over the crust.

Sprinkle the remaining oat mixture over the jam layer of the bars. 

Bake for 35 minutes, or until the tops become golden brown.

Remove from the oven and allow to cool completely.

Sprinkle the tops with powdered sugar and then using the parchment paper overhang, pull the bars out of the baking dish.

Slice for serving and enjoy!