Put flour, 1/4 c. sugar, baking soda, baking powder, salt and oats in food processor and pulse 15 times. Add cold butter cut into bits and process until pea size pieces form. Put into bowl, add 3/4 cup buttermilk and lemon zest and stir with fork to combine. Scoop out onto floured surface and knead 6 times. Divide dough in half and form each half into circle and pat down until 1 inch high. Cut each circle into 6 wedges. Brush tops with remaining 1 oz. buttermilk and sprinkle with remaining 1 T. sugar. Bake on parchment paper on baking sheet in 425 oven for 15 - 18 minutes.