These chocolate oatmeal cupcakes are rich, moist, and phenomenal! The quick oats lend a moistness and richness to the batter, though you won't taste the oats. The frosting turns into a layer of chocolate softness with a slightly crisp exterior. YUM!
Preheat oven to 350. Line muffin tins and set aside.
In a bowl, combine quick oats with very hot coffee, stir well, and let stand. Cover to keep warm.
Meanwhile: In the bowl of a stand mixer, cream butter and both sugars with paddle attachment, until smooth and creamy. Add vanilla and eggs, and mix well.
Add flour, baking soda, salt, and cocoa straight into mixing bowl, and mix with paddle attachment just until incorporated (do not over mix)
Add hot oat/coffee mixture to batter and mix until incorporated. Add mini chocolate chips, and stir by hand. If your oat/coffee mixture was warm enough, the mini chips should melt into batter during stirring.
Divide batter into lined muffin tins, filling almost to the tops. Bake approx. 18-20 minutes, or just until a toothpick inserted in centers comes out with few moist crumbs attached (not completely clean.)
Let cool in muffin tins.
To make the frosting: In a heavy saucepan, melt butter, sugar, and milk together over medium-low heat, stirring constantly. Bring to a boil, and immediately reduce heat to low. Add mini chocolate chips and marshmallows, constantly stirring until melted and smooth. Remove from heat, and allow frosting to cool about 10 minutes.
Stir again, and use frosting while it's quite warm (not liquid, but not crystallized yet.) Spread onto tops of cupcakes, and let cool.
Notes
*Leftover cupcakes can be stored in airtight container at room temp for a day or two.