Combine the flour, oats, sugar, salt, baking soda, cinnamon and nutmeg in a medium bowl.
Drizzle the butter and orange juice over the flour mixture, stirring until moistened (mixture will be crumbly).
Reserve a 1/2 cup of the oat mixture. Press remaining oat mixture into the bottom of an 11 x 7–inch baking dish that has been coated with cooking spray.
Prepare the filling:
Combine the cranberries, sour cream, granulated sugar, flour, vanilla, and rind in a medium bowl.
Spread the cranberry mixture over the prepared crust. Sprinkle the remaining reserved oat mixture evenly over filling.
Bake for 40 minutes or until the edges are golden brown. Cool completely in the pan on a wire rack.