For The Shortbread Crust:

1. Spray a 13 x 9 inch pan with vegetable spray. Cut a piece or parchment paper that fits the bottom of the pan with excess paper to come up over the long sides and hang down, like a sling.
2. In a large bowl, combine the flour, sugar and salt. Whisk to combine. Add the cold butter and use a pastry blender to cut the butter into the flour mixture until the mixture resembles fine crumbs.
3. In a small prep bowl, combine the milk and almond extract and add it to the flour mixture. Lightly stir together then knead with your hands until the milk is distributed and the mixture holds together, but is not wet.
4. Sprinkle the dough over the parchment paper in the pan and use your fingers to press the dough evenly into the pan to create the crust. Refrigerate for 15 minutes.
5. Preheat the oven to 375°. When the oven is heated and the dough is chilled, bake it for 12-15 minutes until just firm in the center.
6. Spread the jam evenly over the hot crust with an offset spatula.

For The Crumble Topping:

1. In a large bowl, combine the flour, sugar, cinnamon and salt. Cut in the 8 tablespoons of butter until the mixture resembles fine crumbs. Add the sliced almonds and stir until well combined.
2. In a small bowl whisk together the egg and milk. Add it to the almond mixture and stir to evenly combine, until the mixture resembles clumps. Sprinkle the crumble topping over the jam.
3. Bake in the hot oven for 25-30 minutes or until golden brown. Rotate pan 180° halfway through baking to ensure even doneness. Cool completely. Cut into bars.