Preheat the oven to 350°F (175°C).

In a bowl, cream together the softened butter and granulated sugar until light and fluffy.

Beat in the egg and vanilla extract until well blended.

In a separate bowl, whisk together the flour, baking powder, and salt. Gradually add this to the butter mixture, mixing until just combined.

Spread half of the dough in the bottom of a greased baking pan.

Spread the raspberry jam over the dough layer.

Crumble the remaining dough over the jam layer.

Bake for 12 minutes or until the edges are lightly golden.

Allow to cool before cutting into squares.