Combine water, cardamom, and coffee grounds in a large jar or cold brew coffee maker. Let steep in refrigerator or on countertop for 12-24 hours.
Pour coffee through fine mesh bag or cheesecloth into another jar. Discard coffee grounds.
Heat sweetened condensed coconut milk in microwave for 10 seconds so that it will combine with iced coffee.
Pour coffee into glass with ice and sweetened condensed coconut milk.
Notes
*Grind coffee grounds coarsely in a coffee grinder for a slow extraction. You are looking for coffee grounds the size of breadcrumbs or course sugar.The cold brew coffee will last 7-10 days in the fridge. The sweetened condensed coconut milk will last about a week in an airtight container in the fridge.