Preheat oven to 350°F. Grease a 15×10×1 pan or 9×13 (if using, adjust bake time).
Cream butter and sugar. Add eggs one at a time, beating well; add vanilla.
In separate bowl, combine flour and salt; add to creamed mixture. Mix until incorporated.
In another bowl, beat cream cheese, sugar, vanilla until smooth; add egg and blend.
Spread 3 cups of the crust batter in the bottom of the prepared pan.
Gently spread cheesecake mixture over crust.
Top with peach pie filling. Drop remaining batter in pieces on top of filling.
Bake 25–30 minutes (or up to 35 if using larger pan) until set.
Cool on wire rack completely.
Mix glaze ingredients and drizzle over cooled bars.
Chill bars (≈3 hours or overnight) before slicing and serving.