Preheat your oven to 180°C (350°F). Line your baking pan with parchment paper.

In a small saucepan, melt the chopped chocolate and butter together over low heat. Stir until smooth and let it cool slightly.

In a large mixing bowl, combine the caster sugar and eggs. Whisk them together until well blended and creamy.

Pour the melted chocolate mixture into the sugar and egg mixture. Stir well to combine.

Sift in the plain flour, cocoa powder, and a pinch of salt. Gently fold the dry ingredients into the wet ingredients using a spatula.

Add the halved cherries to the batter. Fold them in gently until evenly mixed.

Pour the batter into the lined baking pan and spread it out evenly.

Bake in the preheated oven for about 25-30 minutes. The edges should be firm, and the center should still be a bit soft.

Remove the cake from the oven and let it cool in the pan for about 10 minutes. Then, transfer it to a cooling rack to cool completely.

Once cool, slice the cake into squares or rectangles. Serve plain or with a sprinkle of powdered sugar, whipped cream, or vanilla ice cream.