Peanut Butter and Blackberry Jam Cupcakes - Oregon Raspberries & Blackberries

Ingredients

• 1 LB frozen blackberries
• 1 cup sugar
• Zest and juice of 1 lemon
• or use store bought Oregon blackberry jam
• 2¼ cups all-purpose flour
• 2 teaspoons baking powder
• ½ teaspoon fine sea salt
• ¾ cup sugar
• ½ cup plain unsweetened whole milk Greek yogurt
• ½ cup olive oil
• 1½ teaspoons vanilla
• ½ cup smooth peanut butter
• 4 tablespoons unsalted butter, softened
• 2 cups powdered sugar, sifted
• 1 teaspoon vanilla
• 2 to 3 tablespoons milk, cream, or half and half
• Halved blackberries, for