In a large mixing bowl using an electric hand mixer mix together sugar and butter until combined (it won't come together entirely but mix until lumps of butter are creamed).
Mix in egg, egg yolk and vanilla extract. Mix in melted chocolate then mix in sour cream.
Add about 1/5 of the boiling water at a time, mixing until combined after each addition. Once water has all been blended mix batter on medium-low speed for 1 minute.
Divide batter among prepared muffin cups, filling each about 3/4 full. Bake in preheated oven until set and toothpick inserted into center comes out clean, about 17 - 20 minutes.
Remove from oven, transfer to a wire rack and cool 10 minutes, then transfer to an airtight container (one that doesn't touch tops. I like to do this to seal in moisture) and allow to cool completely before frosting.
Once cool frost with strawberry buttercream frosting and top with a chocolate covered strawberry. Store in an airtight container in refrigerator (for best results serve within the day at room temperature).
Place freeze dried strawberries in a small resealable bag, seal bag and crush strawberries to a fine powder with a rolling pin. Sift through a fine mesh sieve into a bowl to remove seeds, set aside.
Strain strawberry puree through a fine mesh sieve and measure out 3/4 cup, then pour into a small saucepan set over medium-low heat.
Simmer puree, stirring occasionally until reduced by about two thirds to a 1/4 cup, about 10 - 14 minutes (measure and if it isn't quite 1/4 cup then return and continue to simmer, if it's not reduced to correct amount it will make the frosting runny).
Pour reduced puree into a small bowl, then freeze or refrigerate, stirring occasionally until fully cooled.
In the bowl of an electric stand mixer fitted with the paddle attachment, whip butter until pale and fluffy.
Mix in powdered sugar, reduced strawberry puree, freeze dried strawberry powder, lemon juice, and vanilla and continue to mix until frosting is pale and fluffy. Tint with color if desired.
Melt chocolate in a small microwave safe bowl on 50% power in 30 second increments, stirring between intervals, until melted and smooth.
Dip strawberries in chocolate, let excess run off then transfer one to each cupcake.
Recipe source: Cooking Classy