We drove about 100 miles to a blueberry farm last week and it was incredible. The change in scenery did as much good for my mental state (and imagination) as the blueberries do for this cake.
The lemon mascarpone is fluffy, and not too sweet, and the perfect compliment to the sweet (and purple) blueberry frosting. Of course, if you want your filling to be more sweet, more power to you, grab that powdered sugar and get to dumping, stirring and beating.
And another thing, I used mascarpone in this recipe, but truth be told, you can use cream cheese, if you don't want to take the time to look for mascarpone (it's usually in the fancy cheese section of your local grocery store, fyi).
What you will need:
For the cake:
Duncan Hines Yellow Cake mix. haha.
For the lemon mascarpone filling:
8 oz mascarpone (or cream cheese)
1/2 cup whipping cream
juice of 2 lemons
zest of of 2 lemons, plus a little extra
4 heaping tablespoons powdered sugar
For the Blueberry Frosting:
1 cup fresh blueberries
1/2 cup water
3 cups powdered sugar
1 cup (or 2 sticks) of butter
1 teaspoon vanilla
What you will do:
Bake cake per instructions on box for two 8 inch rounds. Cool.
Place fresh blueberries and water in small saucepan and bring to boil. Once boiling, turn heat to medium heat and allow to simmer for 8-9 minutes, stirring often. Now strain the berry juice through a fine mesh sieve, discarding the blueberry skins. Set aside thickened berry juice to cool.
In a large mixing bowl beat butter for 3-4 minutes, until nice and fluffy, with a hand mixer (or stand mixer, with whisk attachment, if you have one.) Now add the powdered sugar, one cup at a time. Add the blue berry juice and vanilla and mix well.
Now make the Lemon Mascarpone filling:
Place mascarpone, whipping cream, lemon juice and powdered sugar in medium sized mixing bowl and beat until filling starts to become thick and fluffy, then add the zest, and beat again. Taste to see if it is sweet enough for you. If not, add more powdered sugar, one tablespoon at a time.
Now assemble the cake.
Place one round cake on cake stand and apply a thin layer of blueberry buttercream to cake, it's okay if you can see the cake through the frosting, this layer of frosting is just to lock in all those crumbs, so that you will not see them on the finished product.
Now carefully place all of your lemon filling on top of the frosted cake round and smooth it out with a flat sided spatula. Sprinkle a little more zest onto the top of the filling.
Next step is optional, as it is a bit precarious. Take the remaining cake round and place in the palm of your hand, gently frost one side, and then VERY CAREFULLY place (frosting side down) onto the cake round that has the lemon filling on it. So now you should have cake, blueberry buttercream, lemon filling, blueberry buttercream, cake. PHEW. Finish crumb coating the top cake round and sides of cake.
Very carefully place the entire cake and cake stand into the freezer to set up.
30 minutes to 1 hour later, remove cake from freezer and use remaining buttercream to frost the cake, going over the top and sides of cake, smoothing and covering "blemishes" as you go.
Optional: top with fresh blueberries and lemon zest. And enjoy on Father's Day, like we will, or anytime the mood strikes...which is pretty often around these parts...