Blackberry Peach Cinnamon Cake - Oregon Raspberries & Blackberries

Ingredients

• 1 cup unsalted butter, room temperature (226 grams) - 2 sticks
• 2 ½ cups granulated sugar (500 grams)
• 1 cup egg whites from a carton - about 7 egg whites (235 grams)
• 3 cups cake flour (360 grams)
• 2 ½ tsp baking powder (10 grams)
• 2 tsp ground cinnamon (6 grams)
• 1 tsp fine table salt (6 grams)
• 1 ½ cups full-fat sour cream, room temperature (380 grams)
• 1 tsp vanilla extract (4 g)