Step 1

Heat the oven to 350 F. Grease an 8-inch square cake pan with cooking spray or softened butter. Line the pan with a long sheet of parchment paper that extends up and over two opposite sides of the pan.

Step 2

In a large bowl, whisk together the flour, sugar and salt. Pour in the melted butter and vanilla and, using a large dinner fork or your hands, stir until the dough holds together when squeezed. Add the egg and continue to mix until incorporated.

Step 3

Press 2/3 of the dough firmly and uniformly into the bottom of the prepared pan with your fingers. Evenly spread the jam over the top and sprinkle the remaining dough in a decorative layer over the jam.

Step 4

Bake for 35 minutes, rotating at the halfway point, until the crumbs are golden brown. Run a knife around the edges of the pan that are not covered with parchment and let the bars cool to room temperature on a wire rack before slicing and serving.

Step 5

The bars are best eaten the day they are made, but will keep for up to three days at room temperature, lightly wrapped in plastic wrap. They will soften as they sit.