Lightly grease an 8" or 9” square pan and line with a parchment sling. Grease the sling too.

To make the bars: In a large saucepan, place the butter, brown sugar, and salt. Cook over medium heat, stirring regularly with a flexible spatula or wooden spoon, until the butter melts.

With the pan off-heat, stir the mixture vigorously for 30 seconds, then add the egg and vanilla; mix until combined.

Add the flour and baking powder, then stir gently until combined. Transfer the batter to the prepared pan and use a small offset spatula to smooth it into an even layer.

Preheat the oven to 350°F with a rack in the center.

To make the frangipane: In the same saucepan (still off-heat) or bowl, place the butter and brown sugar. Use a spatula to vigorously stir them together until light and fluffy, 2 to 3 minutes.

Add the egg and almond extract, mixing until incorporated. Add the flours and salt and continue mixing until combined.

Dollop the frangipane evenly across the top of the batter. Aim for 16 to 20 small dollops of frangipane.

To add the topping: Top the frangipane with small spoonfuls of jam; 16 to 18 spoonfuls provides an even distribution, and a scant teaspoon cookie scoop works well here. Use the tip of a thin knife or toothpick to slightly swirl the jam with the frangipane. Sprinkle the sliced almonds over the top.

Bake for 30 minutes (9” pan) to 34 minutes (8” pan), until the edges start to pull away from the side of the pan and the frangipane is lightly golden, puff and just set.

Remove from the oven and allow to cool completely, in the pan, on a wire rack.

When cool, remove the bars from the pan using the parchment overhang as handles. Garnish with a light sprinkling of non-melting or confectioners' sugar, then cut into slices before serving.

Store any leftover raspberry bars in an airtight container for several days at room temperature or store them in the refrigerator for a firmer texture. Freeze the bars, well wrapped, for longer storage.