Truffle biscuit cake

Ingredients

• 145 grams (5.1 ounces) flour
• 140 grams (4.9 ounces) sugar
• 140 grams (4.9 ounces) boiling water
• 110 grams (3.9 ounces) heavy sour cream
• 110 grams (3.9 ounces) vegetable oil
• 95 grams (3.4 ounces) eggs
• 45 grams (1.6 ounces) cocoa powder
• 5 grams (0.2 ounces) baking powder
• 2 grams (0.07 ounces) salt
• 120 grams (4.2 ounces) warm milk
• 50 grams (1.8 ounces) sugar
• 20 grams (0.7 ounces) cocoa powder
• 200 grams (7.1 ounces) chocolate 33.6%
• 100 grams (3.5 ounces) chocolate 54.5%
• 210 grams (7.4 ounces) whipping cream
• 40 grams (1.4 ounces) butter