Yummy Blackberry Mascarpone Filling for Cake

My birthday was just a few days ago, though we celebrated it the week before, with our guests. One of the guests, Heidi, had her birthday just a few days before mine, so we celebrated together. Luckily, we both love white cake with white icing, so that part was a no-brainer. I did play with the white cake recipe just a bit, to see if I could get it to be more moist. For me, the recipe is delicious as is. I found it someplace on the web but I am not sure exactly where. Wherever I found the recipe I use, it is quite wonderful, but you know, I just have to tinker. Tweak. Nudge. 

White Cake with Blackberry Mascarpone Filling

The reason I tinkered with this recipe at all is because last year for my husband's birthday I made a Maraschino Cherry Cake. He is a total Maraschino cherry fiend, so I thought this cake would be a treat. I had used this white cake recipe as the basis, and added in a 10-ounce jar of cherries with some of the juice. The cake looked lovely. It tasted great. Unfortunately it was just so dry it was very hard to enjoy. Looking ahead to trying this Maraschino cake again, I'd been planning to do some research on how to make that cake (and any cake) more moist. There just happened to be a site out there with a lot of tips, some of which I decided to try. Off the top of my head, some of the tips were:

• if possible, use brown sugar instead of white sugar
• if possible, use whole eggs, or add more yolks
• mix a dry instant pudding mix with the dry ingredients for the cake
• add one (8-oz) carton of yogurt or sour cream to the batter
• use more sugar than called for
• add more butter or some oil

There were more tips (go here for that most informative site), but these were ones I recall. For the white cake I was going to make for our birthdays, I would not be adding whole eggs or yolks, and even less use brown sugar. I did decide to try adding one vanilla pudding mix with the dry ingredients, but I will probably not use that particular tip again. I could taste the artificial flavors of the pudding. It was still really good cake, and possibly more moist, but at least for the white cake recipe itself, I will be leaving well-enough alone.

So, although I was making white cake and white icing for our birthday cake, I did decide to make a filling that was different. I know Heidi loves fruit pies, particularly berries. I have made a fruit pie for her once, but this time I wanted to try something new. I wanted to use blackberries, to make the filling berry flavored and colored, and I wanted to use Mascarpone for some tang and to cut the sweetness. My first dilemma was to figure out how to make the filling taste of berries without adding too much liquid. The last thing I wanted was for the layers to squash the filling out, making the cake look like it had a few spare tires.

White Cake with Blackberry Mascarpone Filling and fresh blackberries

Finally I came up with an idea. I would use some seedless blackberry jam. I chose Polaner's only because it had no added sugar, per se (I know it has sugars, but it is not as sweet as some). If you use a jam with seeds or bits of fruit, press it through a strainer first. I do not suggest using jelly as it is too difficult to get it to meld into the icing. I used a version of my standard icing recipe and just added in some of the blackberry jam. It was too pale (I felt) so I added a little red food coloring. Unfortunately, this removed any trace of the pretty pale purple and turned it solid pink. Oh well. I do have some blackberry flavor extract, so I added in a tiny bit of that, as well as 1 tablespoon of Chambord liqueur. Chambord is raspberry flavored, but I just wanted to up the berry flavors as much as possible. I didn't add the Mascarpone until the icing was finished, and then only mixed until it was just all incorporated. This filling was absolutely stellar!

I had sliced the two layers of the cake in half, making 4 layers. The filling went onto the first half, and then I sliced fresh blackberries lengthwise and set them onto the filling. I did the same on the next two layers. Then I went ahead and made the white icing and frosted and decorated the cake with that. This filling did separate a little, looking slightly curdled, but I was not intending it for the outside of the cake anyway. As a filling, the flavors were just fabulous. Except for the artificial flavor component in the cake itself, this cake was (to me) just to-die-for. Here is the filling recipe as I made it:

Blackberry Mascarpone Buttercream Filling

Makes enough to fill an 8 or 9-inch cake, layers cut in half (three inner layers)

2 sticks unsalted butter, softened

White Cake with Blackberry
Mascarpone Filling and fresh blackberries

4 cups confectioners' sugar, sifted
4 tablespoons (1/4 cup) seedless blackberry preserves (not jelly)
1 teaspoon vanilla extract
½ teaspoon blackberry flavor
1 tablespoon Chambord liqueur, optional
1 carton (8-ounces) Mascarpone cheese, softened
1 small carton fresh blackberries, sliced in half lengthwise

Make sure the butter is soft. If room temperature still has the butter too hard, hold it in warm hands or use the microwave in short 2 - 5 second bursts to soften, but not melt. One or two short microwave bursts should be enough. Place the softened butter into the bowl of a stand mixer on medium speed or higher and beat it for 8 minutes, until very, very light and creamy-pale, stopping to scrape sides of the bowl once or twice during the 8 minutes. Add in the blackberry preserves and beat to combine. Add in the confectioners' sugar all at once and mix on very lowest setting until it is moistened. Add the flavorings to combine, then increase the speed to medium or medium high and beat until very light and fluffy, about 5 or 6 minutes more. Add the softened Mascarpone cheese and beat until just combined.

Filling the cake layers

Spread the filling onto the first cake layer, evenly. Set blackberries, cut side down onto the filling. Top with the next cake layer and repeat. Do this once more, then top with the remaining cake layer and frost the cake as desired. 



My passion is teaching people how to create a harmony of flavors with their cooking, and passing along my love and joy of food, both simple or exotic, plain or fancy. I continue my journey in ethnic and domestic cuisines, continuing my journey to explore diverse culinary experiences and hopefully to start you on a journey of your own. Join me also at A Harmony of Flavors on Facebook, and Pinterest.