Pre-heat oven to 350° (180° celsius). Grease and flour an 8" pie pan (20 centimeter). A spring form pan is my recommendation.
In a large bowl whisk together flour, sugar, baking powder and salt, add butter using a pastry blender or fork combine to form a crumbly mixture, add egg and continue to mix only until still crumbly.
Add approximately 2/3 of the crumbly mixture to the cake pan, lightly press down on the crumbs to firm it up slightly, spread the jam evenly on top and sprinkle with remaining crumb mixture.
Bake for approximately 30-40 minutes or until lightly golden on top. Let cool. Serve with vanilla ice cream if desired. Enjoy!