Low FODMAP Rustic Rhubarb Cake

Ingredients

• 3/4 cup (109 g) plus 2 tablespoons low FODMAP gluten-free all-purpose flour,
• 3/4 teaspoon baking powder; (use gluten-free if following a gluten-free diet)
• 1/4 teaspoon salt
• 1 1/4 cups (248 g) plus 1 tablespoon sugar, (divided)
• 2 large eggs, (at room temperature)
• 1 large egg yolk, (at room temperature)
• 1/4 cup (57 g) unsalted butter, (melted)
• 1/4 cup (61 g) lactose-free sour cream or full fat yogurt
• 1 tablespoon vanilla extract
• 1 teaspoon lemon zest
• 12 ounces (340 g) rhubarb