To make beet puree: Peel two small beets and cut into large chunks. Place in a small pan with enough water to cover and bring to a boil. Simmer until the beets are tender, about 20 minutes. Place the beets and a tablespoon or two of the water into a food processor and process until very smooth.
You can freeze this cookie dough - just drop onto a cookie sheet and place in a freezer for one hour. Then remove and place the cookie dough balls into a freezer bag. Store in the freezer for up to three months.