Line a 10 inch cast iron skillet with parchment paper. Set it aside for now.
Combine the instant espresso and hot water in a small dish. Stir it together to dissolve the instant espresso, then set it aside for later.
In a small bowl, combine the all-purpose flour, baking powder and salt. Set it aside for now.
In your mixing bowl, whisk the eggs to break them up and make them frothy.
Add in the brown sugar, granulated sugar, melted butter and vanilla extract. Whisk until combined.
Stir in the dissolved instant espresso.
Stir in the dry ingredients, and whisk until combined.
Stir in the chopped pecans.
Spread the batter in your prepared baking dish, and bake for 25-30 minutes or until they test done with a wooden pick.
Allow the bars to cool in the pan for 10-15 minutes.
Make the Glaze
Combine the powdered sugar and vanilla extract in a small dish. Mix with a small whisk or a fork. Add just enough milk (1/2 teaspoon at a time) to make it into a glaze that can be drizzled.
Drizzle all over the top of the cappuccino bars.
Cool completely.
Cut into bars and enjoy!
Notes
Try making these with hazelnuts instead of pecans, and adding 1/2 teaspoon of hazelnut extract to the batter!
If you don't have a cast iron skillet, this can be made in a 9" square baking pan or a round cake pan. You may need to adjust the baking time. Use a wooden pick to check for doneness.