Preheat the oven to 350 degrees. Grease a muffin tin with nonstick spray.
In a large saucepan, bring cherries, sugar and water to a boil. Reduce heat; cook and stir until thickened and rhubarb is tender. Cool slightly. Transfer to a food processor or blender and blend until mixture is smooth; set aside.
For crust: place the flour, pecans, butter, confectioners' sugar and salt in a food processor; blend until crumbly. Press the mixture into the bottom and a portion of the way up the sides of muffin tin wells . Bake for 10 to 15 minutes or until lightly browned.
Meanwhile, in a saucepan over medium heat, whisk the egg yolks, sugar, lemon juice, zest and cherry mixture until blended. Add butter; cook until butter is melted, whisking constantly. Pour into prepared crust.
Bake at 12-15 minutes longer or until center is almost set. Cool completely. Refrigerate for at least 1 hour. Just before serving.