Pour some milk into a saucepan and gently warm it over low heat until it's just about to simmer. Take it off the heat and toss in some lavender. Let it chill and steep for about 20 minutes. Strain out the lavender bits and let the milk cool down completely to use later.

Grab another saucepan and mix sugar with ½ cup of water. Bring it to a nice boil over medium-high heat, then lower the heat a little and add more lavender. Let the syrup simmer for 10 minutes, then take it off the heat and let it cool down. Strain out the lavender with a sieve.

Preheat your oven to 350°F (177°C) and grease your cake pans (or line them with parchment paper). Mix some sour cream and the chilled lavender milk until well combined. Set that aside.

Sift the baking powder, cake flour, salt, and sugar into a big mixing bowl. Give it a whirl at low speed for 4-5 seconds.

Add the unsalted butter, half of our lavender milk + sour cream combo, and vanilla. Crank the speed to medium and let it mix until all dry ingredients moisten (1 minute). Pause the mixer, scrape the bowl's bottom and sides, and mix again.

Whisk the eggs well in another bowl with the rest of our lavender milk and sour cream mix. With your mixer running at medium speed, pour this egg mixture into our batter in three batches, giving it a quick mix for about 13-16 seconds after every addition. Stop again, scrape the bowl, and give it one final mix for another 15 seconds.

Pour your batter evenly into your cake pans. Bake for 20 to 22 minutes until cooked through. Stick a small toothpick in the middle - if it looks clean when you pull it out, you're good to go. Let the cakes cool entirely in the cake pans on a wire rack.

Carefully slice off a very thin layer from the tops so the cakes look flattened. Brush each cake generously with our lavender syrup.

Grab a big bowl and your mixer. Toss in the cream cheese and butter and let them mingle at medium speed 'til creamy (2 minutes).

Add the confectioners' sugar, vanilla, milk, and a pinch of salt with your mixer on low. Crank up the speed to high and let it beat for about 3 minutes until fluffy.

(Optional) Split your frosting into two halves and tint one of them purple (2 to 3 drops of food coloring).

Pop one of your cake layers onto your serving plate or cake stand and slather on a thin white frosting.

Pipe a nice ring of frosting around the cake's outer edge to make a "dam." Pipe another ring of frosting a bit further in to form a "bull's eye." Next, spoon some blackberry jam into the gaps.

Repeat everything with the second cake layer. Once you've stacked all your layers, give the whole thing a thin coat of frosting (if you still have any frosting left).

Refrigerate for 13-15 minutes, then spread your purple frosting on the sides and top. Finally, top it off with fresh blackberries.

Refrigerate the cake for about 20 minutes before digging in. Enjoy!