Preheat the oven to 220 °C.
Place a 23 cm cast iron or ovenproof frying pan in the oven to preheat for 15 minutes, or until very hot.
To make the date caramel sauce, place the dates in a small bowl. Add boiling water and bicarb soda. Soak for 10 minutes, or until softened.
Place the dates and their liquid in a high-speed blender. Add the maple syrup, coconut oil and vanilla. Blend until smooth. Add the coconut cream and blend to make a smooth pourable sauce. Transfer into a small bowl or jug and set aside.
Whisk the eggs, almond milk, maple syrup and vanilla together in a medium bowl. Sift in the buckwheat flour, arrowroot, cinnamon and salt. Whisk to make a thin batter. Pour in 1 tablespoon of the coconut oil and whisk to combine.
Working quickly, carefully remove the hot pan from the oven. Add the remaining coconut oil to the pan and swirl to coat the base. Pour in the batter and scatter with blueberries. Return the pan to the oven. Bake for 15 minutes, or until puffed up around the sides and browned.
To serve, place a heatproof surface, such as a small chopping board on the table for putting the hot pan on.
Once cooked, present the puffed pancake to the table immediately, as it will deflate quickly. Drizzle with date caramel sauce, scatter with toasted coconut and cut into wedges. Serve with lemon.