Set oven to 350F Generously butter and flour your bundt pan, making sure to get into all the nooks and crannies. Don't skip this step! Whisk the dry ingredients together in a large mixing bowl. Whisk the wet ingredients together in a another bowl. Add the wet ingredients to the dry and whisk until just combined, don't over mix. Pour the batter into the prepared pan and bake for 45-50 minutes, until a toothpick inserted near the center comes out without wet batter clinging to it. Set the pan on a cooling rack for 15 minutes. Stir the sugar and cinnamon together for the topping. Invert the cake onto a plate. Brush with the melted butter, and sprinkle generously all over with the sugar.