Preheat the oven to 350°F. Line a 9 x 5 loaf pan with parchment paper, leaving an overhang on the short sides.
Place the sugar and almond paste in a large bowl. Beat until the mixture is crumbly. Add the butter and beat again. Add the egg and vanilla; beat to blend. Add the flour, baking powder, and salt; beat once more.
Spread 2/3 of the batter in the pan. Top with the preserves. Dollop the remaining batter over the top.
Bake until golden brown, about 25 minutes. Cool in the pan, then lift out and cut into 8 bars.