Preheat oven to 350F and prepare cupcake trays by lining with cupcake liners.
In small saucepan over medium heat, combine 1 cup milk and dark chocolate, stirring until chocolate is completely melted.
Increase heat to medium-high, stir constantly until mixture begins to bubble and stir in cocoa powder. Remove from heat and whisk until smooth. Set aside.
In KitchenAid, combine canola oil and sugars, beat on medium speed for about 30 seconds, scrape sides of bowl, and stir again on medium-high speed for another 30 seconds -- until ingredients are well-combined (mixture will be very thick and grainy).
Add egg and vanilla, beat well.
In a separate bowl, combine flour, baking powder, baking soda, and salt.
With mixer on low-medium speed, gradually stir in flour mixture to butter/sugar mixture, pausing to scrape down the sides of the bowl occasionally.
Pour the cocoa/dark chocolate liquid into the mixer and beat on medium speed until combined.
Scrape down sides of bowl and add 3 Tbsp milk, stir on medium speed again so all ingredients are combined.
Pour batter into cupcake liners, filling cupcake liners ⅔ of the way full.
Bake on 350F for 18 minutes (toothpick inserted into middle of cupcake should come out clean).
Allow to cool completely before frosting.
Raspberry Frosting
First, prepare a raspberry reduction by combining raspberries and sugar in a small saucepan over medium-low heat.
Once berries begin to release their juices, increase heat to medium-high and stir constantly, mashing the berries with the back of your spoon as you go. Bring to a boil (still stirring constantly) and cook 6-8 minutes until mixture has reduced.
Run through a strainer to remove seeds and pulp (I add 1 Tbsp of seeds back in to the juices for a little bit of texture, this is optional) and allow to cool completely before using in frosting. Discard leftover seeds/pulp.
Once raspberry juices have cooled completely, prepare the frosting by creaming butter until smooth.
Gradually add powdered sugar and stir until combined.
Add in raspberry juices and stir well.
Spread or pipe frosting on top of cooled cupcakes.
Keep uneaten cupcakes stored in the refrigerator in an airtight container.