Pre-heat oven to 350F (180C). Grease and flour an 8" pie pan (20 cm). 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!
Notes
How to Store the Crumb Cake
The cake should be covered with foil or plastic wrap to keep it from drying out. Properly stored, freshly baked crumb cake will last for about 1 to 2 days at room temperature. If your house is hot or in order to last longer wrap it in plastic and store in an air tight bag or container and store in the fridge. It will last up to a week when properly stored.Baked Crumb Cake can also be frozen, wrap the cake tightly with plastic wrap, and place in an airtight freezer bag or container. Properly stored, the cake will last up to 3 months.