Preheat oven to 350 degrees and grease a 9" x 13" baking pan.
Melt the butter in a saucepan and add the pecans. Cook over medium-low heat until the pecans are toasted and the butter turns brown. About 15 minutes.
Strain the pecans from the butter. Chill the butter for about 20 minutes.
Cream the chilled butter and brown sugar until light and fluffy, about 3 minutes. Add the syrup and mix until incorporated.
Beat in the eggs and vanilla until combined
Add the dry ingredients and pecans; mix until just combined.
Pour mixture into the prepared pan. Bake for 35 - 40 minutes until nice and golden
Combine the glaze ingredients and drizzle over the blondies when cooled.