Pour the jar of cherries into a sieve and let the excess liquid drip off.
Preheat the oven to 180°C, top/bottom heat.
In a mixing bowl, whisk together margarine, sugar, vanilla sugar, and salt on KitchenAid Speed 8 (KS8) with the whisk attachment for 8-10 minutes, or until the mixture becomes almost white and very airy.
In a separate bowl, sift together the flour and baking powder.
Set the Standmixer to a slower speed (KS4) and gradually add spoonfuls of flour, alternating with a splash of soy milk. Once the flour and milk are incorporated, scrape the sides of the mixing bowl with a spatula and mix for 30 seconds on a faster speed (KS6).
Pour 2/3 of the batter into a baking tray lined with parchment paper and spread it evenly.
Sift cocoa powder into the batter and add the splash of 10g soy milk. Mix on medium speed (KS6) until the cocoa powder is incorporated, scrape the sides of the bowl, and mix again for a few seconds. Don’t overmix the batter.
Pour the remaining batter onto the baking tray, spread it evenly, and distribute the cherries on top.
Bake the cake for 35 to 40 minutes, or until a wooden skewer comes out clean.
Let the cake cool down while continuing with the pudding cream.