Berry gradient cake, heart-throbbing enchanting purple, romantic to the end, today's mood is purple.

Melt the butter in a water bath, mix it with milk, then cool it to make butter milk.

Beat the eggs, add granulated sugar, and continue to whip until there are no bubbles. When lifting the egg mixture, you should be able to draw a figure-8 on the surface.

Sift in the bread flour and gently fold until evenly mixed, then sift in the cake flour and continue folding until there is no dry flour.

Pour in the butter and milk, and stir evenly to make the cake batter.

Preheat the oven to 160°C, pour the batter into the mold and spread it slightly. Place it in the oven and bake for about 45 minutes until the surface is golden and springs back slightly when pressed.

Take it out and let it cool on a rack, unmold it, and melt the chocolate in a double boiler, then let it cool.

Whip the cream until clear patterns appear, and put about 2/3 of it into a piping bag.

Place the cake on the turntable, and while turning it, pipe the cream from the center all the way to about one-third of the way to the edge. Mix the remaining cream with coloring, and continue to pipe in the remaining one-third of the space along the edge.

Repeat the previous step to get the cream of the final layer's color, squeeze it onto the cake, and smooth the cream with a spatula.

Start placing the blueberries about 1cm from the edge of the cake surface, and finally drizzle with chocolate.