Make the Glaze
Preheat the oven to 350° and coat a 12-cup mini Bundt cake pan with vegetable cooking spray. In a small bowl, whisk the flour with the pie spice, baking powder, baking soda and salt. In a large bowl, using a handheld mixer, beat the butter with the granulated sugar at medium speed until fluffy. Beat in the egg and vanilla. Add the dry ingredients and the sour cream in 2 alternating batches. Spoon the batter into the prepared Bundt cups. Bake in the center of the oven for 25 minutes, until the cakes are risen. Let cool slightly, then invert onto a rack to cool completely.