Very Simple, Extremely Delicious Chocolate Dessert Blocks

This is a very, very simple dessert. ItThere are no complicated operations, simply follow the recipe's instructions to mix the ingredients together and bake it. It's not brownie, it's like a brownie.
Besides soaked rum raisins, you can also add your favorite chopped walnuts, hazelnuts, almonds, etc. into it. Once baked, it will return to you a surprising flavor.
Rum Raisin Chocolate Blocks
(Reference quantity: One 6-inch round mold)
Ingredients:
Low-gluten flour 40g, Butter 50g, Dark Chocolate 85g, Dark Rum 20g, Raisins 30g, Caster Sugar 40g, Milk 45g, Eggs 1, Cocoa powder (for dusting)
Making Process

Soak raisins and rum together. Soak raisins in rum for a while until they become soft.
In another bowl, cut butter and dark chocolate into small pieces and put them into the bowl.

Heat chocolate and butter together over a double boiler and constantly stir until completely melted into liquid, be careful not to splash water into the bowl while stirring. After melting, take the bowl out of the water.
Add caster sugar, stir until well combined, then add eggs and milk, stir until well combined (whisk the eggs first, then add to the mixture. Do not stir too vigorously to avoid producing too much foam).

Add flour, continue to stir until smooth.
Stir into a smooth batter. Pour the soaked raisins with rum together into the batter, stir until well combined.

Pour the batter into a 6-inch round mold with a thin layer of butter to prevent sticking (you can skip the butter, but it's recommended for easier removal). Bake in a preheated oven at 180°C (middle rack) for 25-30 minutes to bake. After baking and cooling, place in the refrigerator for 1 night, take it out, dust a layer of cocoa powder on the surface, then cut into pieces to eat.
Tips:
1This chocolate block doesn't contain any leavening agents, so its texture is dense and thick, similar to brownie but even softer. The addition of rum and raisins brings it a richer flavor. Cut into small pieces, it's perfect for tea time.
2The chocolate block doesn't change color obviously during baking, so pay close attention to the baking time. When baking, it will rise around the edges first, then gradually rise in the middle. When the center part also expands, it means it's baked. If you overbake it, the texture will be dry.
3Dark chocolate can be used as baking-specific chocolate brick, or you can use ready-made chocolate. Using button-shaped dark chocolate is more convenient and saves time. The cocoa content of 55% dark chocolate will produce the finished product that is more in line with most people's taste.
4Rum is a wine that pairs very well with raisins and chocolate, so Rum Raisin is a combination we often see. In this dessert, rum brings a more layered fragrance to chocolate. During baking, most of the alcohol will evaporate, so don't worry too much about the alcohol problem.

Why is rum often used in baking?