In a medium sauce pan combine granulated sugar and water; heat over medium until sugar is dissolved and has come to a boil. Zest and juice the orange; set aside 1 Tbs of the zest and add ½ cup of juice to the pan along with the grated carrots. Let simmer for 20 minutes, remove from the heat and stir in the orange zest, seeds from the vanilla bean, and 4 Tbs all purpose flour.
Preheat the oven to 350 degrees F. In a food processor combine 1 cup all-purpose flour, brown sugar, old fashioned oats, salt, baking powder, and baking soda; pulse to combine. Add in the butter and pulse until a loose crumb is formed. Reserve 1 cup of this crumb mixture and press the remaining into the bottom of a greased 8X8 square baking pan. Bake until golden, about 10-13 minutes.
Spread the carrot mixture over the warm crust and then sprinkle the reserved crust mixture evenly over the top. Return to the oven and bake 30-40 minutes, or until the carrot filling is bubbling and the top is browned.