Preheat the oven to 325℉. Spray a 24-cup mini muffin pan with nonstick cooking spray.

For the crust: In the bowl of a stand mixer fitted with the paddle attachment, combine the butter, cream cheese, and granulated sugar. Beat on medium-high speed until light and fluffy, about 4 to 5 minutes. Add the flour and mix on low until the dough just comes together.

Using a 1-tablespoon scoop, form 24 balls of dough. Place each ball into a muffin cup, then use wet fingers to press the dough into the bottom and up the sides, forming a cup. Freeze for 15 minutes.

For the filling: In a medium bowl, whisk together the brown sugar, melted butter, corn syrup, vanilla, bourbon (if using), salt, and egg. Once smooth and combined, fold in the chopped pecans.

Remove the crusts from the freezer and fill each cup with 1 heaping teaspoon of filling. Top each with a pecan half.

Bake until the crusts are golden brown and the filling is set, about 20 to 25 minutes. Let cool for 5 minutes before removing the tassies from the pan with an offset spatula. Let cool completely on a wire rack.