Combine water, espresso powder, rum and raisins in a saucepan and heat over medium heat to a gentle simmer. Simmer 5 minutes or until raisins plump. Set aside to cool.
Attach wire whip to KitchenAid Stand Mixer. Add egg yolks and sugar to mixer bowl, turn to speed 4 and mix 1 minute or until thick and sugar has completely dissolved. Reduce to Stir speed, gradually add milk and mix until well combined.
Pour mixture into clean saucepan. Heat over medium-low heat, stirring constantly for
5-6 minutes or until hot but not boiling. Mixture should coat the back of a spoon. Do not boil or it may curdle. Remove from heat and stir in espresso raisin mixture. Refrigerate mixture until cold.
Attach clean wire whip and bowl to mixer. Add cream and whip on speed 8 until soft peaks form. Reduce to Stir speed, add espresso mixture and mix just until blended.
Attach KitchenAid Ice Cream Maker attachment to mixer. Turn to Stir speed, pour mixture into freeze bowl and churn for 20 minutes or until soft set. Ice cream can be served immediately or for a firmer texture, transfer to a container and freeze for several hours.