Preheat oven to 350˚F (175˚C).
For the sauce, in a medium pot over medium heat, combine raspberries and sugar. Cook until bubbling, about 5 – 7 minutes. Reduce to medium-low heat, cook for 3 more minutes. Strain the mixture through a sieve into a medium bowl. Discard the seeds. Set the sauce aside to cool.
For the crust, in a medium bowl, combine cookie crumbs and 1 tablespoon sugar. Add the melted butter and mix well. Press the mixture firmly onto the bottom of a 6-inch spring form pan. Bake in the oven for 10 minutes. Remove from oven and cool on a cooling rack.
Reduce oven to 325˚F (165˚C).
Bring a large kettle of water to a boil. Keep warm.
For the filling, in a large mixing bowl with an electric mixer fitted with a paddle attachment, add cream cheese. Beat at medium speed until smooth and fluffy, about 3 minutes. Add sugar and beat to combine. Add salt and vanilla extract, and mix well. Add 1 egg, mix on low-speed until blended. Add remaining eggs, one at a time. Do not overmix.
Wrap the outside of the spring form pan with two layers of aluminum foils. Make sure the bottom and side are well covered, so water can’t seep through during baking. Pour the filling into the pan.
To make the swirl, using a small spoon, put about 10 drops of raspberry sauce on top of the filling. With a toothpick or skewer, draw through the dots of sauce to create swirls.
Reserve the rest of the sauce into an airtight container and keep in the fridge.
For the water bath, carefully transfer the cheesecake pan to a large roasting pan, and put in the oven. Slowly fill the roasting pan with enough hot water to come half way up the sides of the cheesecake pan (without getting any water into the cheesecake). Bake for 65 – 75 minutes, until the cake is almost all set. Do not overbake. The small center of the cake should jiggle a little. Remove the cheesecake pan and the roasting pan together from oven. Cool for 5 minutes. Remove the cheesecake pan from water and cool completely on a cooling rack. Once cooled, cover the cheesecake pan with aluminum foil and chill in the fridge overnight.
When ready to serve, run a sharp knife around the edge of the cake. Remove spring form pan and top with fresh raspberry. Serve each slice of cake with raspberry sauce, whipped cream and fresh raspberry if desired.