1 tbsp. fresh squeezed lemon juice
1 tsp. ground cinnamon
1 tbsp. breadcrumbs
2 tbsp. demerara (light brown) sugar
1/4 cup white granulated sugar
1 1/2 pounds apples
6 tbsp. sour cream
1/2 tsp. vanilla bean paste
2 egg yolks
1 1/3 sticks unsalted butter, room temperature
3/4 cup powdered sugar
1/4 tsp. sea salt
2 tsp. baking powder
2 1/2 cups all-purpose flour