Start by combining the buckwheat, lentils, and quinoa in a large vessel, cover with plenty of filtered water and add a splash of apple cider vinegar (optional). Soak for 8-12 hours. Drain and rinse very well.
Add the grains and lentils to a blender (you may need to work in batches) with the 5 cups / 1250ml water, coconut sugar, and vanilla. Blend on high until the batter is silky smooth.
Heat a medium-large skillet over medium-high heat. Add a little bit of cooking fat (expeller-pressed coconut oil or ghee) to the pan, making sure to coat the bottom. Pour in some batter until it’s about halfway to the edges, then tilt and rotate the pan so that the batter reaches the edges and makes a circle. Cook for a few minutes until the bottom is golden brown, flip and cook for another couple minutes until golden. Remove from heat and repeat (if you’re using a non-stick or stainless steel pan, you likely won’t need to add any more fat between crepes).
While you’re cooking the crepes, make the fillings. Place the berries, maple syrup and salt in a food processor and blend on high until smooth. Taste and adjust the flavours as desired. Set aside. Next combine all the cream ingredients, taste and adjust the flavours as desired. Set both fillings aside and get ready to assemble!
To assemble the cake, place one cooked crepe on a serving plate and spread with the berry jam in a thin, even layer, then place another crepe on top. Spread the cream over this layer, then place another crepe on top. Repeat this process until you’ve reached the top!
Serve the cake immediately, or let it sit and absorb the filling flavours for up to 12 hours. I prefer it freshly made, but it does keep very well, covered and stored at room temperature. Serve with maple syrup, if desired. Keep any leftovers refrigerated for up to three days (but best enjoyed right away!).