Chocolate Toffee Surprise Cupcakes - Cupcake Fanatic

Ingredients

• 1 cup boiling water
• 1/2 cup unsweetened cocoa
• 1/4 tsp instant espresso (optional)
• 1 1/2 cups flour
• 1 tsp baking soda
• 3/4 tsp baking power
• 1/4 tsp salt
• 3 Tbsp unsalted butter, at room temperature
• 2/3 cup sugar
• 1 tsp vanilla extract
• 1 large egg
• 1/2 cup plain fat-free yogurt
• 1 (3.5 oz) Green & Black’s Organic Toffee Chocolate Bar (or your favorite toffee chocolate bar)
• 3 Tbsp unsalted butter
• 1 1/2 cups powdered sugar
• 2-3 Tbsp low-fat milk
• 2 Tbsp plus 2 tsp toffee bits