The night before, be sure to soak your cashews and place your ice cream maker bowl in the freezer to chill.
To a high speed blender add soaked, drained cashews, coconut milk, oil, maple syrup, vanilla, sea salt and arrowroot starch. Blend until creamy and smooth, scraping down sides as needed.
Taste and adjust sweetness as needed, adding more cane sugar or maple syrup if desired - I found 1/4 cup maple syrup and 1/4 cup cane sugar to be perfect (amounts as original recipe is written // adjust if altering batch size).
Transfer to a mixing bowl and cover. For best results, chill overnight or for at least 5-6 hours. If in a rush, 1 1/2 to 2 hours in the freezer is sufficient.
Once your base is chilled, prepare raspberries by adding to a bowl and mashing with sweetener. Set aside.
Assemble your chilled ice cream maker and pour in the chilled ice cream batter. Churn until creamy and thick and resembles soft serve - about 40-45 minutes.
In the last 30 seconds of churning, add in 1/2 of the raspberries and let churn until slightly swirled. Turn off machine.
Transfer ice cream to a freezer-safe container and smooth flat with a spoon, swirling in the remaining amount of raspberries. Tap on the counter to help settle and remove any air bubbles.
Cover securely and freeze for 4-5 hours or until firm. Before scooping, set out for 10-15 minutes to soften. Keeps in the freezer for up to 1 week, though best within the first few days.