Walnut, coffee & vanilla cake with bitter chocolate

Ingredients

• 230 grams (8.11 ounces) egg whites
• 165 grams (5.82 ounces) sugar
• 10 grams (0.35 ounces) vanilla sugar
• 150 grams (5.29 ounces) almond crumbs
• 40 grams (1.41 ounces) cornstarch
• 4 grams (0.14 ounces) alkalized cocoa
• 1 gram (0.035 ounces) salt
• 30 grams (1.06 ounces) almond flakes, for sprinkling
• 110 grams (3.88 ounces) egg yolks
• 120 grams (4.23 ounces) sugar
• 5 grams (0.18 ounces) vanilla sugar
• 560 grams (19.75 ounces) milk
• 48 grams (1.69 ounces) cornstarch
• 32 grams (1.13 ounces) espresso
• 160 grams (5.64 ounces) butter, 82.5%
• 5 grams (0.18 ounces) rum
• 200 grams (7.05 ounces) coffee custard
• 100 grams (3.53 ounces) bitter chocolate
• 100 grams (3.53 ounces) butter, 82.5%
• 30 grams (1.06 ounces) powdered sugar
• 80 grams (2.82 ounces) cream, 35%
• 125 grams (4.41 ounces) mascarpone
• 25 grams (0.88 ounces) powdered sugar
• 0.5 vanilla pod