In a large bowl, whisk together flour, cocoa powder, brown sugar, granulated sugar, baking soda, salt and cinnamon. Set aside.

In the bowl of a stand mixer fitted with the paddle attachment, combine egg, buttermilk, olive oil and vanilla extract and mix on medium speed for about 15 seconds until somewhat combined.

Add dry mixture to the bowl and combine on low speed, gradually increasing speed to medium, until completely combined. Add wine and beat to combine again.

Pour batter into prepared cupcake liners, filling ¾ full. Bake for 12-18 minutes, or until a toothpick inserted into the center of a cupcake comes out with a moist crumb.

Let cool in pan for 5 minutes, then transfer to wire rack to cool completely.

Push the mixture through a fine mesh strainer over a small bowl to remove all the seeds and chunks. Let the liquid cool completely - you can place it in the fridge to speed up the process.

In the bowl of a stand mixer fitted with the paddle attachment, beat butter until smooth. Add blackberry juice, salt and 1 cup powdered sugar and combine on low speed, gradually increasing speed to high, until completely combined and fluffy. Add more powdered sugar, ½ cup at a time, to taste. If you want to make your frosting's color more bold, add food coloring and beat to combine, one drop at a time, until you've reached your desired shade.

Spoon frosting into a piping bag fitted with the tip of your choosing and frost cooled cupcakes. Serve and enjoy!