Pre-heat oven to 425°F. Line two baking sheets with parchment paper and set aside.
In a large bowl, combine flour, baking soda, baking powder, salt and sage.
Cut in the butter, blending with a fork or pastry blender until butter is in small, pea-sized pieces.
In a separate medium bowl, combine the pumpkin puree and Greek yogurt. Mix the greek yogurt/pumpkin mixture into the dried ingredients. You may need to use your hands to get it completely blended.
Knead dough out onto a floured surface 6 or so times. Pat or roll out to a thickness of 0.5 inches. I found it easier to pat since the dough is a bit sticky. Cut out circles of 2-3 inches in diameter {I used a glass}.
Transfer circles to baking sheets, brush the tops with melted butter, and place a sage leaf on each biscuit. Bake for 11-14 minutes, until biscuits are firm to the touch and cooked through.
Cool slightly and serve.