Chocolate Raspberry Muffins - Washington Red Raspberries

Ingredients

• 2 cups (plus 1 cup) frozen Washington red raspberries (divided)
• 1 1/2 cups whole wheat pastry flour
• 1 cup buckwheat flour
• 6 tablespoons unsweetened cocoa powder
• 2 teaspoons baking powder
• 3/4 teaspoon sea salt
• 1/2 teaspoon baking soda
• 6 tablespoons cold unsalted butter (cut into pieces)
• 1/4 cup dark brown sugar
• 1/4 cup granulated sugar
• 2 large eggs
• 1/2 cup plain 2% yogurt
• 4 ounces bittersweet chocolate (cut into pieces)