To bake the strawberry cake:

1. In a mixer, beat the butter and sugar at medium speed until light and creamy, about 3 minutes.
2. Add eggs one at a time, mixing on medium speed for 30 seconds after each one, before adding the next. Scrape down to the bottom of the mixing bowl with a spatula to make sure all of the butter and sugar are mixed in.
3. Whisk together the flour, baking powder and salt. Add a third of the flour mixture to the mixer and mix on low speed only until incorporated.
4. In a blender or food processor, blend fresh/frozen and freeze-dried strawberries until smooth.
5. Whisk together milk, strawberries and vanilla. Add half of the strawberry mixture to the mixer and mix at low speed only until incorporated. Mix in another third of the flour, then the rest of the strawberry mixture, and then the final third of the flour mixture.
6. Divide the batter between three greased 8” pans. Tap the pans on the counter to level the batter and then bake at 350C or 175C for 23 minutes. When the cake springs back up when you poke it, the cakes are baked. Don’t bake any longer than this or the cakes will dry out.
7. Let the cakes sit in the pans for 5 minutes to cool slightly and then turn over onto a wire rack and leave them to cool.

To make the strawberry buttercream filling and frosting:

1. Mix butter and sugar together at low speed for 4 minutes, until smooth.
2. Blend freeze-dried strawberry in a blender or food processor to make a powder. Mix the powder into the buttercream.
3. Add milk 1 tablespoon at a time until the buttercream is the consistency of peanut butter or stuff whipped cream.

To layer and frost the cake:

1. Spread a bit of buttercream onto the middle of a cake board or flat plate or platter. Press the first cake layer onto the buttercream to secure it in place.
2. Spread strawberry buttercream to cover the top of the cake layer and then place the next cake layer on top. Spread strawberry filling on top and then add the final cake layer.
3. Spread strawberry buttercream to cover the cake. Smooth with a cake comb or offset spatula. To add texture, drag a spoon in arc motions, pushing it gently into the frosting to make swirls.
4. Serve this cake at room temperature. You can refrigerate it for 2 days but take it out of the fridge at least 2 hours before serving.