Preheat oven to 400 degrees F. and line a pizza pan with parchment paper.
Place flour, sugar, baking powder, cinnamon and salt into a food processor bowl. Pulse to combine ingredients. Add cubed ice cold butter pieces into bowl, pulsing until combined into flour mixture. Transfer to a large mixing bowl. Pour in buttermilk, add pumpkin, buttermilk, sour cream and almond extract, mixing gently until dough forms. Fold in white chocolate chips.
With floured hands transfer dough to prepared pizza pan. Press and form into 1/2 inch thick round. Brush tops of scone dough with heavy cream and sprinkle with sugar and cinnamon mixture. Bake for 20-23 minutes, until baked through and turning golden brown around edges. Remove from oven and let cool for 20 minutes. Use a pizza cutter to slowly and carefully cut wedges into dough. Place wedges on serving plate.
To prepare icing, place powdered sugar into a medium mixing bowl. Slowly whisk in heavy cream until thick and smooth. Drizzle over top of scones and serve warm or room temperature.