Blackberry-Lavender Opera Cake

One of my co-workers wanted me to make her a birthday cake, which is a neat trick when all your cake pans and decorating equipment are on the other side of the country.

I only heard of Opera cakes recently.  I pass a fancy bakery sometimes when I make deliveries, and was stuck in traffic.  I looked up their menu while the construction trucks decided which way they needed to move.  One item was a slice of Opera cake for $7.

When I got home, I looked up recipes to find out why one slice was so pricey.  Opera doesn't mean going to a show in the name of this confection, it refers to the amount of work.  There are multiple layers of ingredients, different frostings, ganache, and it doesn't really make sense to make one of these things if you're not charging a lot per slice.  They sound good though, a lot like chocolate tiramisu, but not as oozey.

For this cake, I'm stealing the layer concept, but cutting down on the work.  My co-worker loves blackberries, so I'm scattering them on whipped cream frosting between layers of a modified lavender cake that have been brushed with lemon simple syrup.  I turned the last of the Gryffindor buttercream slightly purple to spread on the top, then drizzled white chocolate ganache for a design.  It's the 3-hour version of a cake that normally takes two or three days.

Cake
3/4 C sugar
*1 tsp culinary lavender
3/4 C margarine
3 eggs, room temperature
*2/3 C milk
1-1/2 C cake flour
1 Tb baking powder
1/4 tsp salt

1.  The day before, combine sugar and dried lavender.  Place in a sealed container to make lavender sugar.  You can do this up to a week before.  Any longer, and it won't get more intense.

2.   Grease an 11"x15" cake pan, line with waxed paper, and grease the paper.  Start preheating the oven to 350º

3.  Sift together flour, baking powder, and salt.  Set aside until needed.  Run the sugar through the sifter over a mixing bowl to remove most of the lavender buds.  Discard buds.  Cream together sugar and margarine with the paddle until smooth.  Scrape the bowl and add eggs one at a time, scraping between additions.

4.  Add flour and milk in stages, stirring to combine each.  Once all the ingredients are in the mixer, beat for 2 minutes.  Scrape the bowl, and beat an additional minute.

5.  Pour into cake pan.  Spread batter evenly, making sure to get the corners.  It's going to be very thin.  Smack the pan a few times on the counter to remove any bubbles.  Bake until springy, about 15-18 minutes.  Cool in pan for 10 minutes, then carefully turn out on a cooling rack and remove the paper.  Cool completely before moving on.  You can even freeze the cake and come back to it another day.

Whipped Cream Frosting
1 C heavy whipping cream
1/2 C powdered sugar
*2 Tb unsalted butter, room temperature

1.  In mixer with whisk, beat cream to soft peaks.  Add powdered sugar and beat to incorporate.

2.  Cut butter into small chunks and change to paddle attachment.  Beat butter into whipped cream until smooth and stiff peak consistency.  Chill until ready to use.

Lemon Syrup
*2 Tb lemon juice
2 Tb sugar

1.  Bring juice and sugar to a boil and stir until sugar is dissolved.  If desired, a bit of Limoncello can be added.  Allow to cool to room temperature.

Assembly

1.  Use a ruler to cut the cake into 4 equal quarters.  Stack them, picking one corner to line up perfectly.  I also did half of the pieces upside-down and made sure two inside edges and two outside were on each edge.  A little OCD, but it kept the cake relatively level.  Trim off any uneven or crunchy edges and start snacking.

2.  Rinse the blackberries and dry with paper towels.  Cut in half lengthwise.

3.  Place bottom cake layer on cake board or serving platter.  Brush with syrup.  Spread with a 1/4" layer of frosting, then dot with blackberries.  Repeat with the next two layers.

4.  If desired, tint remaining frosting before spreading on top piece of cake.  I realized the layer didn't actually have to be on the cake to do this, so the rest of it sat in the fridge for a few minutes, firming up, while I did this step.  Set top layer on the cake, then allow it to chill while you prepare the ganache.

5.  Microwave 1/4 C of white chocolate on 50% power in 1 minute increments until soft.  Add a few drops of cream or milk at a time until you get a consistency that can be drizzled or piped.  I put mine in a baggie with the end snipped off and piped the drizzle.  If you want, you can use royal icing to write on the cake.

6.  Keep cake chilled until half an hour before serving.  The whipping cream will spoil if left out.

Serves about 12, depending on the size of the slices

Difficulty rating  :-0