Soak the dates in warm water for 30 minutes, then drain, peel, and remove the pits.
Grind the almonds in a coffee grinder or food processor until fine; if your coconut flakes are coarse, grind them the same way first.
Add the pitted dates, ground almonds, coconut flakes, and coconut oil to a blender and blend until the mixture holds together like plasticine.
Line a small cake tin (about 7 in / 18 cm ) with cling film and press the dough evenly into the bottom, then place the tin in the freezer while you make the cream.
Pour the coconut milk into a saucepan, add the blueberries, cornstarch, Earl Grey tea, Jerusalem artichoke syrup, and agar-agar, and stir to combine.
Set the pan over medium heat and cook, stirring occasionally so nothing catches on the bottom, until the cream comes to a boil.
Let the cream simmer for 1–2 minutes, then blend it until completely smooth.
Pass the cream through a fine sieve to catch the tea leaves and blueberry skins, leaving a delicate, smooth filling.
Take the base out of the freezer, pour the cream over it, and tap the tin gently on the worktop to release any air bubbles on the surface.
Freeze the cake for 4 hours until set, then slice and serve.
