walnut jam cake

INGREDIENTS

• 1 1/4 cups walnuts (4 1/2 ounces or 130 grams), toasted (in a shallow baking pan at 350°F for 10 minutes) and cooled
• 2/3 cup (150 grams) sugar
• 1 stick unsalted butter (4 ounces or 113 grams), cut into pieces
• 4 large eggs
• 1 teaspoon pure vanilla extract
• 1/2 cup (2 1/4 ounces or 65 grams) all-purpose flour
• 1/2 teaspoon (2 grams) baking powder
• 1/2 teaspoon (3 grams) salt
• 1 teaspoon fresh lemon juice (optional)
• 1/2 cup (150 grams) jam or preserves (apricot or raspberry are recommended; I used black currant)
• 2/3 cup (160 grams) chilled heavy cream
• 1/4 cup (60 grams) sour cream
• 1 teaspoon sugar
• 1/2 teaspoon pure vanilla extract