Spray a (6-cup) bundt pan with cooking spray and set aside.

In a medium bowl, whisk together the flour, baking powder, and salt. 

Cut 1/2 cup butter into small cubes and pour into the dry ingredients.

Use a fork to mix in the butter until the dry ingredients are crumbly and about the size of peas.

Slowly pour in 1 cup milk, mixing until a dough forms.

Use your hands to knead the dough about 10 minutes, until smooth.

Pour the dough onto a lightly floured surface and pat into a 10 inch round.

Cut the dough up into 1 inch pieces and set aside.

Combine the granulated sugar and cinnamon in a gallon sized zip top bag. Close the bag and shake to mix. 

Pour the cut pieces of dough into the bag of cinnamon sugar. 

Gently knead the bag until each piece of dough is coated in cinnamon sugar.

Remove the dough pieces and arrange them evenly in the bundt pan.

Set the Instant Pot to Sauté. Pour in the brown sugar and remaining 1/2 cup butter. Whisk until the butter is melted and the brown sugar is dissolved, about 2 minutes.

Turn off the Instant Pot. Pour the butter mixture over the top of the monkey bread pieces in the bundt pan. 

Remove the cooking pot and clean it. Put it back inside the Instant Pot.

Add 1 1/2 cups water to the Instant Pot and place a trivet inside.

Cover the bundt pan with a paper towel and aluminum foil, crimping the edges to discourage water from getting inside the pan.

Create a foil sling and carefully lower the bundt pan into the Instant Pot.

Close the lid and set the pressure release to sealing.

Press the Manual or Pressure Cook button and adjust cook time to 21 minutes.

Allow the pressure to release naturally for 5 minutes and then quick release the remaining pressure.

Remove the bundt pan using the foil sling. Remove the foil and paper towel from the top of the pan and let cool on a rack for 5 minutes. 

While the monkey bread is cooling, whisk together the powder sugar and remaining 2 teaspoons milk in a small bowl. Set aside.

Turn the bundt pan over onto a plate and wiggle the pan to allow the monkey bread to be released. 

Drizzle the monkey bread with the vanilla icing while it is still warm. 

Enjoy immediately and store any unused portion in an air-tight container at room temperature for up to 3 days.