Preheat your oven to 350°F (175°C)., In a mixing bowl, cream together the softened butter and powdered sugar until light and fluffy., Mix in the vanilla extract., Gradually add in the flour and salt. Mix until combined, being careful not to overwork the dough., Press the shortbread mixture evenly into the bottom of your prepared muffin tin or mini cheesecake pan., In a small saucepan, combine the crushed pineapple, sugar, cornstarch, water, and lemon juice over medium heat., Stir constantly until the mixture thickens into a syrup-like consistency, about 5-7 minutes., Remove the saucepan from the heat and let it cool while you prepare the cheesecake layer., In a large mixing bowl, beat the cream cheese with an electric mixer on medium speed until smooth and creamy, about 2-3 minutes., Gradually add in the granulated sugar and continue mixing until well combined., Add the vanilla extract and sour cream, beating until just incorporated., Add the eggs, one at a time, mixing on low speed after each addition. Be careful not to overmix., Spoon a generous amount of the cheesecake mixture over the shortbread layer in each muffin cup., Add a layer of the cooled pineapple mixture on top of the cheesecake layer., Place the muffin tin in the preheated oven., Bake for 18-20 minutes or until the edges are set, and the centers have a slight jiggle., Remove from the oven and let them cool in the pan for 10 minutes., After cooling slightly, transfer the mini cheesecakes to a cooling rack. Allow them to cool completely before refrigerating., Chill the cheesecakes in the refrigerator for at least 4 hours, preferably overnight.