Gluten-Free Strawberry Cake

Name: Gluten-Free Strawberry Cake
Prep time: 4 h
Total time: 4 h
Cuisine: World Cuisine
Ingredients: 500 g fresh or frozen strawberries; 110 g jam sugar; juice of 1 medium lemon; 800 g barista-style oat milk (gluten-free); 30 g vinegar; 140 g vegan butter, melted; 1 pinch salt; 500 g gluten-free pastry flour; 100 g almond flour; 16 g baking powder; 8 g baking soda; 300 g granulated sugar; 1 liter barista-style oat milk (gluten-free); 240 g granulated sugar; 120 g cornstarch; 4 g agar-agar powder; 15 g vanilla extract, or 1 g vanilla powder (or 1 whole vanilla bean, scraped); 60 g vegan butter (gluten-free, soy-free); 200 g vegan butter, softened (gluten-free, soy-free); 1 full batch of vanilla pastry cream; 1/2 batch of vanilla mousseline; 120 g strawberry jam (gluten-free, vegan); 200 g plant-based whipping cream (gluten-free, soy-free); 1/4 tsp vanilla powder; 500 g strawberries (fresh, medium-sized); 100 ml water; 50 g granulated sugar