Boil water and sugar – turn off heat, add rum and raisins. Let cool to room temperature; chill. Drain before using. Save syrup for the kugelhupf syrup.
Add the syrup from the drained raisins to the ingredients; bring to boil. Use lukewarm.
In a large bowl, combine dry ingredients first. Then add milk and eggs and mix until it comes together. Transfer dough onto a work surface and knead it for 10 minutes until it becomes elastic and smooth; it should not stick anymore. Add butter and continue to knead for an additional 10 minutes until the dough turns smooth and elastic again. A dough scraper helps to clear up the work surface as it goes. The internal temperature of the dough should reach between 72ºF/22ºC to 80ºF/26ºC. Mix in raisins. Transfer Kugelhopf dough into a greased bowl. Cover with plastic wrap or a wet kitchen towel – let rise (first fermentation) for about 2 hours or until it has doubled in size. Transfer dough onto work surface (no extra flour needed). Scale out individual cakes into 20 x 2.6oz/80g portions or 2 x 1.6 lb/750g large cakes. Shape into balls and let rest. Grease mold generously with butter and coat with sliced almonds. Add dough into each mold and press down. Cover Kugelhopf and let proof until it has doubled in volume.
Heat up oven with a pizza stone. Bake kugelhup cakes at 350ºF/180ºC for about 25 minutes. Un-mold immediately and flip on a wire rack to cool.
Soak Kugelhopf cakes in the lukewarm syrup. Then, brush with melted butter cool and dust with powdered sugar. Save remaining syrup. Bon appétit!