Bring raspberries and 1 tbsp maple syrup to a boil over medium-high heat, then lower heat to a simmer for 10 minutes until the raspberries are soft and mashed easily. Mash by hand or in a food processor, then set aside in refrigerator to cool.
Add all ice cream ingredients to a blender and blend for at least 1 minute to help incorporate some air into the mixture. Pour into a loaf pan or resealable plastic container.
Pour cooled raspberry mash on top of ice cream and swirl throughout using a knife.
Freeze ice cream for 4-6 hours, then allow to thaw and soften slightly before serving. Eat immediately and refreeze remaining ice cream.
Be sure to use grass-fed whey and casein (and skip the booze) to keep this recipe paleo. Grass-fed casein can be a bit harder to find than grass-fed whey, so you can use 2 1/2 scoops of whey and skip the casein if necessary. The casein adds an extra level of creaminess that you won't get with just the whey though.