Preheat your oven to 350°F (175°C). Line an 8x8 inch baking pan with parchment paper, leaving some overhang for easy removal later.
In a mixing bowl, combine the flour, salt, and baking powder. Add the cold cubed butter and mix until the mixture resembles coarse crumbs. Stir in the granulated sugar, brown sugar, egg, vanilla extract, and milk until a dough forms.
Set aside 1/3 of the dough for the top crust. Press the remaining dough into the bottom of the prepared baking pan evenly to form the base.
In a small bowl, mix together brown sugar, cinnamon, and flour for the filling. Sprinkle this mixture evenly over the dough in the pan.
Roll out the remaining 1/3 of the dough on a lightly floured surface to roughly match the size of the pan. Place it over the cinnamon filling. If desired, cut slits in the dough to allow steam to escape, or poke with a fork for a rustic look.
Place the pan in the preheated oven and bake for 25-30 minutes, or until the top is golden brown.
Remove from the oven and let it cool in the pan for about 10 minutes before lifting it out using the parchment overhang. Allow it to cool completely on a wire rack.
In a medium bowl, whisk together powdered sugar and milk until smooth. Adjust with more milk for desired consistency.
Once the bars have cooled, drizzle the glaze over the top, and if desired, dust with extra cinnamon.
Cut into squares or rectangles and serve. Enjoy your sweet, homemade pop tart bars!
Notes
For a rustic look, you can poke the top dough with a fork.
Keyword bars, brown sugar, cinnamon, dessert, pop tart