Lemon Curd Cake with Blackberry Buttercream Frosting
Covered with blackberry frosting and filled with homemade lemon curd, this triple-layer lemon curd cake made from scratch with fresh lemon is the ultimate delight for lemon lovers!
I am the official Maker of Food in my household. My husband does so much to keep our household running smoothly — washing dishes, cleaning the kitchen, packing lunches, grocery shopping — but when it comes to making what we eat, that’s all on me.
So it’s not surprising that this continues into birthday celebrations. I make the cakes for everyone else’s birthday… but it also means that if I want a birthday cake, I have to make it myself.
And the really, really big upside to this is: you get exactly what you want. There’s no sending someone to wander around a bakery and guessing. There’s no someone choosing what they like best even though it’s your birthday.
It was my birthday back in June, and I wanted a lemon curd cake with blackberry buttercream, so I made a lemon curd cake with blackberry buttercream. And it was glorious.
How to Make Lemon Cake from Scratch
The base of this cake is very similar to the strawberry layer cake with whipped cream frosting (made earlier this year for my daughter’s first birthday!). The base is a delicious light vanilla cake — hearty enough to hold up to our lemon curd filling, but not dense like pound cake.
To make sure the lemon flavor shines through, we’re using both lemon juice and lemon zest. A lot of lemon cakes call for lemon jello, lemon pudding, or lemon extract. Nothing but real lemon here, friends. I don’t love the artificial lemon flavor in baked goods.
Plus, we don’t want to go too overboard on the lemon flavor, since we’re also using lemon curd as a filling.
Because we’re adding in even more acid from the lemon juice, we’re adding some baking soda into the mix, on top of the baking powder. This gives the cake a little extra lift and helps balance the flavor. Why do we want to add baking soda? It’s time for my favorite subject… kitchen chemistry!
Adding an acid (like lemon juice) to cake batter denatures (unfolds) the proteins in the batter. In small amounts, this makes the cake more tender. However, too much acid – and the cake structure falls apart! Because we’re adding a full 1/3 cup of lemon juice to impart a real lemon flavor to the cake, add baking soda to neutralize the acid. As the baking soda interacts with the lemon juice, carbon dioxide is formed, which gives the cake extra lift.
Lemon Curd Filling for Cake
I love lemon curd. L-O-V-E lemon curd. So obviously, there’s lemon curd in the birthday cake I chose to make for myself.
I used my own homemade lemon curd recipe for the filling. One batch is plenty — you’ll likely have some leftover (to eat with a spoon, obviously). There isn’t an exact scientific amount to put on each layer; feel free to eyeball.
Because lemon curd is so moist (I know, I know — people hate the word, but how else can we describe it? Has such a high liquid content? Is so viscous?), we need a barrier between our cake and the lemon curd — so the curd doesn’t all soak into the cake.
Spread a thin layer of the blackberry buttercream frosting on the base of the cake, piling it up higher around the edges (like this ↓↓↓), then fill the inside with the lemon curd.
Fresh Blackberry Buttercream Frosting
Lemon and blackberry pairs so well together, and the frosting on this lemon curd cake is no exception. A thick layer of frosting, naturally tinted a beautiful shade of pinkish-purple, with just the right amount of tart blackberry flavor.
Since blackberries don’t hold a lot of liquid, we can just toss whole blackberries into the frosting, mixing until smooth, and spread on the cake.
After assembling the cake, I used the leftover lemon curd and thinned it down with just a little heavy cream. This works as a perfect easy glaze to drip down the sides of the cake for some visual contrast – and to let everyone know what lemony goodness is waiting inside!
Storing Lemon Curd Cake
Because of the lemon curd filling, this lemon curd cake with blackberry frosting should be stored in the refrigerator.
The frosted, assembled cake will store well in the refrigerator for 2-3 days. Once cutting into the cake, slices will start to go stale under refrigeration, and is best consumed within another 2 days.
To freeze individual slices, cut the cake, wrap in plastic wrap, followed by a layer of aluminum foil, and freeze for up to 3 months.
Tips and Tricks for Lemon Curd Cake:
- For perfectly flat, non-domed cakes, use Bake Even Strips (or wet cloths soaked in water and wrapped around the outside of the cake).
- For even cake layers, weigh the batter of the cake and divide into three baking pans.
- Short on time? All components of this cake can be made ahead of time. The cake layers can be baked and frozen for up to 3 months. The lemon curd can be made a week or two ahead of time. The blackberry buttercream can be made the night before. The cake can be assembled 1-2 days prior to consuming.
- Store the lemon curd cake in the refrigerator. The lemon curd does require refrigeration.
- To prevent the cut cake from getting stale, wrap leftover slices in plastic wrap or push wax paper against the exposed edge to minimize contact with air.
More Layer Cake Recipes
- Vanilla Layer Cake with Blueberry Cardamom Curd
- Carrot Cake with Lemon Cinnamon Cream Cheese Frosting
- Chocolate Hazelnut Cake
- Chocolate Peanut Butter Cup Cake
- All Cake Recipes »
Frosted cake should be stored in the refrigerator. Remaining slices can be frozen (see "Storing Lemon Curd Cake" section of text). A Bunsen Burner Bakery Original Protocol As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.
FOR THE CAKE:
FOR THE LEMON CURD:
FOR THE BLACKBERRY BUTTERCREAM FROSTING:
Nutrition Information: Yield: 16 Serving Size: 1 slice
Amount Per Serving: Calories: 674Total Fat: 29gCarbohydrates: 99gProtein: 6g
Frosted cake should be stored in the refrigerator. Remaining slices can be frozen (see "Storing Lemon Curd Cake" section of text).
A Bunsen Burner Bakery Original Protocol
As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.