Preheat oven to 350F.
Generously butter and flour a bundt pan.
Sift the flour, baking soda, and salt together.
Beat butter until fluffy.
Slowly add sugar and beat until well blended.
Beat in eggs one at a time.
Beat in extract.
Mix coconut milk and rum.
Beat in flour alternately with the coconut milk mixture, beginning and ending with coconut milk.
Fold in chocolate.
Spoon batter into pan.
Bake about 65 minutes or until a tester inserted halfway between edge and center comes out clean.
Cool in pan for 5 minutes. Turn out and cool completely.