Jotting this down quick so I have it for reference.
12 ounces semi sweet chocolate chips
1 can sweetened condensed milk
1/2 bag mini marshmallows
2 tbsps butter (unsalted)
1/2 tsp instant espresso powder
1/2 tsp salt
1 tsp vanilla extract
Prepare 8 inch square baking pan by lining with parchment and spraying lightly with cooking spray.
In two quart saucepan over low heat, melt together chips, milk, butter, and marshmallows. Once melted, stir in espresso powder, salt, and vanilla. Pour into prepared pan and chill for at least 8 hours before cutting into 1 inch squares. Store in an airtight container in the refrigerator