The day before, prepare the plant-based solution using an immersion blender by mixing the water, NATUR LIN and NATUR EGGLESS. Mix this solution with the sugar, salt, honey and oat milk previously infused with the vanilla pod and lemon zest. Sift the flour and BAKING POWDER, add to the previous mixture and whisk until thoroughly combined. Add the fats, which have melted at 65°C, mixing gently with a whisk. Line the dough with plastic wrap and leave to rest for 24 hours. Butter and flour the tin moulds. Poach the madeleines 3/4 of the way into the tin. Heat the oven to 240°C, place in the oven and switch off the oven for 8 minutes, then continue baking at 180°C until the desired colour is obtained. Turn out while still warm.