Add raisins and golden raisins to a sealable glass container, such as a mason jar, and add enough bourbon to cover them (about ½ cup). Close tightly and set aside for at least 24 hours.
Preheat oven to 350 degrees. Add flour, baking powder, baking soda, spices and sea salt to a bowl and whisk together.
In another bowl, mix sugars, vanilla, eggs, butter, and crushed pineapple.
Add carrots, walnuts, and raisins to dry ingredients then mix together. Add wet to dry and mix, adding any extra bourbon from the raisins.
Divide batter between two greased round pans and bake for about 30 minutes or until a toothpick inserted into the center of each comes out clean.
While the cakes bake, mix together frosting ingredients by hand or with a beater and set aside.
Cool cakes completely then frost. Garnish with chopped pecans, if desired.