Prepare vanilla pudding filling: Using soy milk, sugar, vanilla sugar, and vanilla pudding powder, prepare pudding according to package instructions. Cover directly with cling film and cool completely.
Make yeast dough: Sieve flour into a mixing bowl and make a small well in the center. Gently heat soy milk, dissolve fresh yeast in it, and pour into the well. Add sugar, vanilla sugar, and vegan margarine, then knead everything into a homogeneous dough that releases from the sides of the bowl.
First rise: Shape dough into a ball and make light crosswise cuts with scissors. Cover and let rise in a warm place for 1 hour until the volume doubles.
Make almond topping: Heat vegan margarine, sugar, soy cream, and agave syrup over medium heat while stirring until sugar dissolves. Carefully stir in almond flakes and cool to lukewarm.
Prepare and bake: Briefly knead the yeast dough, then roll it into a greased springform pan. Spread the almond mixture evenly on top. Cover and let rest for 20 minutes. Bake in a preheated oven at 175°C (350°F) for 20 to 25 minutes.
Make filling and assemble: Beat vegan margarine until creamy. Fold in the cooled vanilla pudding 1 tablespoon at a time. Once the cake is cooled, cut it horizontally. Coat the bottom layer with the cream mixture and place the top layer back on.
Chill: Refrigerate for at least 5 hours before serving.