Grape Cake with Balsamic Caramel Swiss Meringue Buttercream
Vanilla cake, filled with grape jam, with Balsamic Caramel Swiss Meringue Buttercream.
Course Dessert
Cuisine American
Keyword cake
Prep Time 1 hourhour
Cook Time 25 minutesminutes
Servings 20people
Calories 350kcal
Author Camila Hurst
Ingredients
Vanilla Cake
2cupsall-purpose flour9 oz, 255 grams
1teaspoonbaking powder
1/4teaspoonbaking soda
1/2teaspoonsalt
1/2cupunsalted butterat room temperature (4 oz, 113 grams)
1 1/2cupsgranulated sugar10.5 oz, 300 grams
3tablespoonsvegetable oil44 ml
3large eggs
2teaspoonsvanilla extract
1cupmilk236 ml
Grape Jam
453 grams grapes I used seedless dark purple grapes
3 tablespoons granulated sugar or maple syrupor sweetener of choice
1 tablespoon lemon juice
3teaspoonscornstarch*see notes
1tablespooncold water
Balsamic Caramel
1/2 cup light brown sugar 100 grams3.5 oz
1/4 cup balsamic vinegar
1/2 cup heavy cream 118 ml
1 tablespoon butter 14 grams0.5 oz
1/4 teaspoon salt
Balsamic Caramel Swiss Meringue Buttercream
4 large egg whites 224 grams, 7.9 oz
1 cup sugar 200 grams, 7 oz
20 tablespoons butter 283 grams, 10 oz
1 teaspoon vanilla extract
1/2 cup balsamic caramel recipe above
Instructions
Vanilla Cake
Pre-heat oven to 350 F.
Grease 2 8-inch round pans. Line with parchment paper. Or butter and flour the pans.
Sift the flour, baking powder, baking soda, salt together. Set aside.
Cream butter and oil together in the bowl of an electric mixer for about 1 minute.
Add sugar. Cream for another 2 minutes.
Add eggs one at a time, waiting for one egg to be incorporated before adding the next one.
Add vanilla extract.
Pour half of the milk in. Mix until combined.
Add half of the flour mixture in the bowl. Stir until combined.
Add the rest of the milk in.
Finally, add the other half of the flour mixture.
Stir just until combined. You don’t want to over mix cake batter, because that might make your cake dry and tough, since the more you mix, the batter starts to develop gluten.
Divide cake batter between the two cake pans.
Bake in pre-heated oven for about 15-20 minutes, rotating in between.
Cakes are ready when they are golden on the outside and cooked on the inside. Insert a toothpick in the cake and if it comes out clean, that means the cake is baked. Or gently touch the top of the cake, if it springs right back, it means the cake is ready.
Remove from the oven. Let cakes cool down for 10 minutes, remove them from the pans. Let them cool down completely before frosting.
Grape Jam
Mixe grapes, sugar, and lemon juice in a small saucepan.
Bring it to a boil, then reduce the heat to medium low, and cook for about 10 minutes, stirring constantly.
Mix cornstarch and water, add it to the jam mixture. Let it come back to a boil and keep stirring and cooking for a few more minutes until it thickens. Don't stop stirring at this point, or the cornstarch will clump up.
Let it cool down for about 5 minutes. Transfer it to the bowl of a small food processor or blender. Puree jam until smooth.
Let it cool completely in the fridge before using it.
If, for some reason, your jam is too liquidy, and not becoming thick and reduced enough, it might be because of the type of grape you are using. In this case, after you’ve processed the jam in the blender, return it to the sauce pan, then mix 1 tablespoon of cornstarch with one tablespoon of water, add it to the jam, and bring to a boil. Let jam boil for a couple of minutes until thickened. Remove from the heat and refrigerate until ready to use.
Balsamic Caramel**
Place brown sugar and balsamic vinegar in a small saucepan. Bring to a gentle boil.
Let mixture simmer over medium heat for about 3 minutes, until thickened and reduced.
Add heavy cream.
Be aware that the mixture will probably splash once you do this.
Bring it back to a boil, and simmer again over medium heat for another 2-4 minutes, until thick.
Add butter and salt. Mix to combine, until butter is melted.
Remove and transfer to a bowl. Let it cool down completely before adding to the Swiss meringue buttercream.
Balsamic Caramel Swiss Meringue Buttercream
Remove butter from the fridge about 30 minutes before you start to make this. We are looking for the perfect butter temperature and consistency. It shouldn’t be hard cold, and it shouldn’t be so soft that is almost melting.
Put whites and sugar in a heatproof bowl.
Place bowl on top of a small pot with simmering water.
Whisk whites and sugar until they temp 140F. Basically you are looking to melt the sugar granules, and also make it so the egg white is in a safe temperature to be consumed.
Once you achieve that temperature, transfer the syrup to your mixer bowl.
Whip with the whisk attachment for about 2 minutes at medium speed, until the mixture looks white, and thicker. At this point, raise speed to high and continue to whip until fluffy and doubled in size. Meringue should have stiff peaks. It can take anywhere from 5-10 minutes to obtain stiff peaks.
Test every so often, so you don’t over whip it.
Start adding the butter that should be slightly softened.
Cut butter into very thin pats. Starts doing one by one with mixer running on medium-high.
Wait for one butter pat to be incorporated before adding the next one.
This whole process could take about 15 minutes. Add vanilla extract.
Once butter is all incorporated add 1/2 cup of the Balsamic Caramel Sauce to the Swiss Meringue Buttercream. The caramel sauce should be at room temperature.
You probably won't have leftover buttercream, but if you do, you can simply store them in the fridge for up to 4 days, or in the freezer, for up to 2 months. Remember to package it really well in sealed air tight containers, or zip loc bags, before freezing.
To use it again, simply let it thaw until it comes to room temperature and beat it briefly to make it creamy again before using.
To assemble
Place one cake layer on a cake plate.
Pipe a ring of frosting around the edges of the cake.
Spread jam in the middle of the cake.
Top with the other cake layer.
Cover with frosting.
Let cake sit in the fridge for a few hours or overnight before serving.
Storage
This cake will last for up to 5 days, covered in the fridge.
Notes
*You can make this jam without the cornstarch, but it might be slightly thinner. I like the jam to be really thick for cake filling. If you don't want to use cornstarch, simply cook the jam for about 30 minutes with just the grapes, sweetener, and lemon juice, until thick, and until a thermometer registers 220 F.**This recipe will make more caramel than what you need for the Swiss Meringue Buttercream. You can store any leftovers for up to 1 month in the fridge, and up to 3 months in the freezer. Or use it to decorate the top of the cake like I did!