Preheat the oven to 350℉/175℃. Grease and line two 8-inch baking pans with parchment paper and set aside.
In a stand mixer fitted with the paddle attachment, cream the room temperature butter with the oil and sugar until creamy on medium speed. This will take about 2-3 minutes, and it'll look a bit grainy and fluffy.
⅓ cup unsalted butter, ¼ cup neutral oil, 1 ⅔ cup white sugar
Add the eggs one at a time, beating well and scraping the bowl after each addition.
In a small bowl, whisk together the flour with the baking powder and salt.
2 teaspoons baking powder, 2 ¼ cups all purpose flour, 1 ½ teaspoons kosher salt
Add ⅓ of the flour mixture, then mix on low. Add ½ the buttermilk. Repeat once more, then end with the flour mixture.
1 cup buttermilk
Pour the smooth cake batter into the prepared pans.
Bake for 30-35 minutes, or until a toothpick inserted comes out clean. Let the cakes cool in the pans for 10-15 minutes before removing and letting them cool completely on wire cooling racks.
Make Strawberry Filling
I recommend making this the night before if possible, or start making it before you bake the cakes! This will give it time to really thicken up.
In a medium sized saucepan, combine the diced strawberries with the lemon juice, lemon zest and sugar. Cook over medium-low heat until it begins to simmer, stir frequently.
2 cups strawberries, 4 tablespoons white sugar, 1 ½ tablespoons lemon juice, zest lemon
Turn the heat to low and let it simmer for 25-30 minutes, it should become very thick. Coat the back of a spoon and if you're able to do that and run a line through it with your finger, then it is ready.
Take off the heat and let cool completely. Store in a large mason jar or airtight container in the fridge for up to 1 week.
Make Frosting
Blend the freeze dried strawberry pieces with a food processor or blender until you have fine crumbs. Set aside.
1 ½ cups freeze dried strawberries
In a stand mixer fitted with the paddle attachment, or in a large bowl with a handheld mixer, beat the butter and confectioners' sugar on low speed.
1 ½ cups unsalted butter, 4 ¼ cups confectioner's sugar
Once combined, turn the speed to medium-high and beat until it becomes very thick.
Stop the mixer and add the vanilla extract, almond extract, salt and strawberry powder. Beat on medium-high speed until light and fluffy.
1 ½ teaspoons vanilla extract, ½ teaspoon almond extract, ¼ teaspoon kosher salt
Turn the mixer on your lowest speed and slowly pour in the cream until the frosting becomes creamy and spreadable - you might not need all the cream!
¼ cup heavy cream
Assembly
Place one cooled cake layer down on a plate or cake stand. Spread a small amount of strawberry frosting on top, then pipe a ring of strawberry frosting on the outer edges of the cake - this will create a barrier so the strawberry filling doesn't leak out!
Take the cooled and set strawberry filling out of the fridge. Place ½ cup (or more if you like, ½ cup is what I used in the images above!) of the filling in the middle and use a small offset spatula to evenly spread it over the cake. Spread it up to the ring of frosting.
Place the second layer on top, then frost the whole cake with the remaining frosting. Enjoy!
Notes
My recipes have been developed and tested in metric grams. I highly recommend using a weighing scale and measuring out your ingredients the metric way. Just click on ‘metric’ above ingredients. Room Temperature: I make sure that all of my ingredients are at room temperature before I start the recipe, so pull out all of the ingredients before you start baking.Using Strawberry Jam: if you don't want to make your own strawberry filling, you can use ½ cup of strawberry jam or preserves instead. Butter: I use European style butter in my recipes. This will make your frosting much creamier and richer.Salt: If you don’t have kosher salt, halve the amount of salt called for in the recipe. 1 teaspoon kosher salt = ½ teaspoon fine salt. I am using Diamond Crystal kosher salt and not Morton Salt which is much too salty! Leftover Frosting + Filling: note that you will have a bit of frosting and filling leftover from this recipe!
Storage: Keep tightly wrapped in the fridge for up to 5 days. Let it come to room temperature before eating.
Making Ahead: You can make the cake layers ahead of time. Bake them and then once completely cooled, wrap in plastic wrap tightly. Store in the fridge for up to 2 days or in the freezer for up to 2 months. If frozen, allow to defrost and come to room temperature before frosting the cake. You can make the strawberry filling a week in advance, keep in a jar with a lid in the fridge.