Preheat oven to 350 degrees F (175 degrees C). Grease a 9-inch pie dish.
Combine sweetener and almond flour in a large bowl; beat in eggs until well mixed. Stir in pumpkin, half-and-half, vanilla extract, and pumpkin pie spice until smooth. Pour pumpkin mixture into prepared pie dish.
Place pie dish into a large baking pan; fill baking pan with about 1/2 inch hot water.
Bake in preheated oven until a knife inserted into the center of the pie comes out clean, 50 to 55 minutes.
