Begin by mixing the ground linseeds (flaxseeds) with the hot water. Let sit for about 10 minutes in the fridge until it becomes gelatinous.
Combine the lemon and orange zest, plant-based milk, lemon juice and vanilla extract. Set aside. In a large bowl, combine the flour, ground almonds, baking powder, bicarbonate of soda (baking soda), salt and cardamom.
Using a stand mixer or hand-held electric whisk, beat the marzipan with the apple sauce. Beat in the vegetable oil and sugar. Continue to beat until smooth. Stir in the milk mixture, followed by the flour mixture. Do not overmix.
Transfer the batter to an airtight container and refrigerate for at least 2 hours. 5. When ready to bake, preheat the oven to 180°C fan (350°F/Gas 4) and line a baking sheet with parchment.
Using an ice cream scoop or a tablespoon, place mounds of the batter 5cm (2in) apart on the baking sheet. Sprinkle over the sugar and almonds for topping.
Bake in the preheated oven for 11 minutes, or until golden, puffed up and the cake-ies spring back when lightly touched. Let cool on the baking sheet for 10 minutes before transferring to a wire rack to cool completely.
ChillThe batter can be stored in an airtight container in the fridge for up to 5 days. FreezeSimply freeze mounds of sugar and almond-topped batter on a plate. Once frozen, wrap airtight and freeze for up to 6 months. Bake from frozen Preheat the oven as above and bake on a lined baking sheet for about 14–16 minutes, or until golden.