Preheat oven to 350F/180C. Line a 9×9-inch pan with parchment paper, leaving enough overhang on the sides for lifting the bars out of the pan after baking. Set aside.
To make the crust: Process flour, granulated sugar, and salt in a food processor for a few seconds until combined. Add butter and vanilla extract and pulse until mixture becomes crumbly and resembles coarse meal. Alternatively, you can crumble all the ingredients together in a bowl using a pastry cutter. Set aside 1¼ cups of the crumb mixture for the topping. Sprinkle remaining crumbs into prepared pan and press firmly into an even layer to form a crust. Bake for about 15 minutes, until the edges are slightly browned. Allow to cool completely on a wire rack before spreading the jam.
To make the streusel topping: Add brown sugar to the remaining crumb mixture and toss with your fingers to combine until large clumps of dough are formed. Stir in almonds and coconut. Cover and place in the fridge until ready to use.
Spread jam over crust and sprinkle with streusel topping (if you prefer less crumbs for the topping, you don't have to use all of it). Bake bars for 20-25 minutes, until streusel is golden brown.
Refrigerate bars for at least 2 hours to let the filling set before cutting into squares.
Bars will keep for 3 days in the refrigerator.