To make the frosting, in a large bowl, use an electric mixer to blend together the butter and yogurt until combined. Add the dry organic frosting mix, then blend until smooth and creamy, about a minute.
Place frosting into a piping bag or plastic storage bag fitted with a star piping tip. Snip off the end of the plastic bag.
For the cake
Pour the Foodstirs Organic Molten Chocolate Minute Mug Cake into a small bowl. Add 2 Tbsp. of hot water and stir with a spoon until well combined. Pour half of the mix in a microwave-safe mug. An 8 oz mug is recommended.
Microwave on high for 30 seconds or until cake is set. Carefully, remove the mug from the microwave, using the handle. The mug will be hot. Let cool for one minute.
Pipe a layer of the frosting on top of the cake, pressing down and pushing the frosting to the edges of the mug.
Pour the second half of the mix on top of the mug. Microwave on high for 30 seconds or until cake is set.
Carefully, remove the mug from the microwave, using the handle. The mug will be hot. Let cool for one minute.
Top with more frosting and a garnish of shaved organic chocolate. The cake is best consumed warm. Enjoy!