Boston Cream Donuts

Bahan-bahan (18 porsi)

• ½ cup heavy cream
• ½ cup whole milk
• ¼ cup granulated sugar
• ¼ cup unsalted butter
• 3 ¼ cup all-purpose flour
• 2 packets rapid rise yeast
• 1 teaspoon salt
• 2 egg yolks
• Vegetable oil for frying
• ¼ cup granulated sugar
• 1 ½ tablespoons cornstarch
• 1 pinch salt
• 1 ¼ cup whole milk
• 1 large egg yolk
• 1 tablespoon unsalted butter
• 1 teaspoon vanilla extract
• 4 ounces semi-sweet chocolate chips
• ⅓ cup heavy whipping cream