In a large glass measuring cup, measure the milk and oil. Add the coffee and stir. Add the dry ingredients and whisk until all the lumps are gone. Spray two 8 oz. coffee mugs with nonstick spray. Pour half of the batter into each mug and add a dollop of Nutella (or peanut butter!) to the center of each. Microwave for 60 seconds on high. You might need to zap it for 10-15 more seconds. Top with whipped cream and garnish with cocoa powder.