Step 1: Preheat your oven to 350°F (175°C). Grease and flour a 9-inch springform pan, lining the bottom with parchment paper for easy removal.
Step 2: In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, ginger, nutmeg, and salt. Set aside.
Step 3: In a large bowl, cream together the 1/2 cup softened butter and granulated sugar until light and fluffy, about 3 minutes. Beat in the eggs one at a time, then stir in the sour cream and vanilla extract.
Step 4: Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Fold in the diced pears gently by hand.
Step 5: Spread the batter into the prepared pan. Arrange the reserved pear slices on top in a decorative circular pattern.
Step 6: Bake for 45-50 minutes, or until a toothpick inserted into the center of the cake comes out clean.
Step 7: While the cake bakes, prepare the glaze by simmering the maple syrup and 2 tablespoons of butter in a small saucepan for 3-5 minutes. Whisk in the powdered sugar until smooth.
Step 8: Once the cake is removed from the oven, let it cool in the pan for 10 minutes, then pour the warm maple glaze evenly over the top. Allow the cake to cool completely before serving.