Place the flour, sugar, salt, baking soda, and butter in the bowl of a food processor and pulse several times until the ingredients are combined and a crumbly dough is formed.
Add the oats and lemon zest. Pulse quickly twice to combine. Press 2/3 of the dough firmly into a greased 9-by-13-inch pan.
Spread the jam evenly over the crust.
Sprinkle the remaining dough over the jam, gently pressing down.
Bake until golden brown. Cool completely, about 2 hours.