Preheat oven to 325°F. In a food processor, process first four ingredients until mixture looks like a coarse meal. Add melted butter and process until smooth. Press firmly into bottom of a 9" springform pan. Wrap the pan with aluminum foil to prevent spills.
Bake 10-12 minutes or until edges are lightly browned; remove from oven, let cool.
In a food processor, process cream cheese until smooth. Add pineapple and process until smooth. Add sugar, salt, eggs, lemon juice, cornstarch and vanilla. Process until creamy and smooth.
Pour into prepared pan. Place pan on a baking sheet and bake at 325°F for about 1 1/2 hours until center is set. Cool for about 1 1/2 hours.
In a medium saucepan, combine pineapple, peach preserves, water, lemon juice and cornstarch. Mix together and cook over medium heat until mixture thickens and pineapple is soft. If mixture gets too thick, add more water, a Tbsp. at a time.
Remove from heat and puree with a blender or food processor until smooth. I used an immersion blender for this step.
Spoon pineapple mixture on top of cooled cheesecake and smooth evenly. Toast coconut in a small skillet over medium heat until it begins to brown, about 3-5 minutes. Remove from heat and sprinkle over the pineapple topping. Cover cheesecake and refrigerate until chilled, at least 6 hours or overnight.
To serve, cut into wedges and garnish with pineapple chunks.