Preheat your oven to 350°F (175°C). Lightly grease a baking tray or line it with parchment paper. For the pastry, combine the flour and butter in a bowl. Rub the butter into the flour until the mixture resembles breadcrumbs. Then, press the mixture into the bottom of the prepared tray to form a thin, even base. Chill in the fridge for 10 minutes to firm up.
Bake the chilled pastry in the oven for about 15 minutes or until it turns golden brown. Remove from the oven and set aside to cool.
While the pastry base cools, prepare the sponge. In a mixing bowl, cream together the softened butter and sugar until light and fluffy. Add the eggs, one at a time, beating well after each addition. Stir in the almond extract.
In a separate bowl, mix the flour, baking powder, and salt. Gradually add this dry mixture to the butter and sugar mixture, alternating with the milk. Stir until combined.
Spread the raspberry jam evenly over the cooled pastry base. Then, carefully spoon the sponge batter over the jam, smoothing it out to cover it evenly.
Sprinkle the sliced almonds on top of the batter. Bake the slices in the preheated oven for about 25-30 minutes or until the sponge is golden brown and a toothpick inserted into the center comes out clean.
Let the Bakewell Slices cool in the tray for 10 minutes, then transfer them to a wire rack to cool completely. Once cooled, cut them into squares or bars.
