Add all ingredients to a small saucepan and mix together until evenly combined and the sugar is mostly dissolved.
Heat over medium-high heat until the liquid just begins to bubble. Reduce the heat to low and cover to simmer.
Simmer covered for 20 minutes - stirring occasionally. After 20 minutes, remove the cover and smash the cranberries and apples with a potato masher or the back of a fork.
Simmer for another 10-20 minutes uncovered until the cranberries sauce reaches desired thickness
Notes
This sauce can be stored in an airtight container in the fridge for up to 4 days.