In a saucepan, add cranberries and pour water till berries are immersed in water enough for cooking (say 1 cup). Let it boil for 5 minutes. Switch off the flame.
Once cranberries are cooled blend to form a puree.
Spray a small square baking dish with cooking spray and line with parchment paper.
Measure 1&3/4 cups of sugar for 2 cups of puree and transfer to a pan. Add salt and coconut oil.
Bring to heat stirring frequently and evenly until it reaches 235F to 245F, or "soft crack" on a candy thermometer.
For testing in water, pour a drop of toffee in a bowl with cold water and press to check if forms a soft ball consistency.
Once it reaches the temperature, switch off immediately. Carefully pour the mixture over the parchment paper Let it sit for a few minutes undisturbed.
It sets at room temperature too or place in the refrigerator for 2 hours. Lift the parchment out of the baking dish and place the toffee on a cutting board.
Use a knife to gently break it into smaller pieces. Store in an airtight container.
Notes
If you like it sweeter use an equal amount of sugar. The pureed cranberries and the sugar in ratio 1:1.