In a food processor, combine walnuts and buckwheat groats and process until a fine meal is formed.Then, add in medjool dates and agave, processing until a sticky ball of dough is formed.In a 6" springform pan (I lined mine with parchment paper), press down crust evenly so the entire bottom of the pan is covered.In a blender, combine all ingredients and blend until smooth and creamy.Pour cheesecake mixture over crust and let settle.Set cheesecake in the freezer for six hours, or overnight.Once cheesecake has set and hardened, top it with any fresh berries you like. From here you can either freeze the cheesecake for a little longer so the berries will be frozen, or serve immediately so the berries are soft (which is what I did).Let cheesecake thaw in the refrigerator for about an hour before serving. It can also be thawed at room temperature for about a half hour or so. The shorter it thaws, the more thick and ice cream-like the texture is. Thawing for longer results in a creamy, fluffy texture. Both are delicious!