2 Tbsp. unsalted butter
1 1/2 Tbsp. (1/2 oz.) chopped milk chocolate
2 Tbsp. sugar
1 large egg
1 Tbsp. unsweetened cocoa powder
1/2 tsp. vanilla extract
2 Tbsp. all-purpose flour
1/4 tsp. baking soda
1/4 cup Josh Pond frozen wild organic blueberries
Whipped cream, mini marshmallows, and/or chocolate syrup, for serving
1. Microwave butter and chocolate in a small bowl at 50% power until just melted, about 1 minute, stirring halfway through.
2. Whisk in sugar, egg, cocoa powder, vanilla, and salt until smooth, then stir in flour, baking soda, and blueberries until blended. Scrape batter into a 12-ounce microwave-safe mug.
3. Microwave for 45 seconds, then stir well. Microwave for 1 more minute (cake should be firm but still slightly fudgy on top); let sit 2 minutes. Top with whipped cream, mini marshmallows, frozen blueberries, and/or chocolate syrup.