Preparation

• Beat the cream cheese with an electric mixer on medium speed until smooth, about 2 minutes. Add the sugar 1/4 cup at a time, beating well after each addition. Add the sour cream, heavy cream, lemon juice, vanilla, and salt and beat just until smooth. Cover with plastic wrap and refrigerate until very cold, about 1 hour.
• Meanwhile, cook the guava paste or jelly and 1/2 cup water in an 8-inch skillet over medium-low heat, mashing with a fork or potato masher, until mostly melted with some smaller chunks, about 6 minutes. Transfer to a bowl and chill in the refrigerator until cooled but still pourable, about 1 hour. (If it does solidify, reheat and rechill.)
• 搅拌奶油芝士混合物放松,then freeze in an ice cream maker according to the manufacturer’s directions until slightly thicker than soft-serve ice cream, about 15 minutes. Transfer to a freezer storage container. Using a wide spatula, gently fold in the guava to create ribbons throughout. Freeze until ready to serve.