• Preheat the oven to 350 degrees F.

Prepare the Baking Pan:

• Grease the Pan - In the baking pan, grease all sides with butter (the butter will help with the next step which is to add parchment paper to the inside of the pan).
• For the Parchment Paper - Cut a piece of parchment paper so that there is enough excess to hang over the sides of the pan (these will be “handles” when removing the blondies from the pan after they cool). 
• Press the paper onto the inside of the pan and smooth it out over the butter which should assist with keeping the paper attached to the pan. 
• In each corner inside of the pan, make creases in the parchment paper and flatten them out so that the paper lays flat against the inside of the pan (so that the parchment paper doesn't bunch up in the corners).
• If there's too much parchment paper hanging off the sides, cut off the excess. 

  Just make sure to leave enough paper hanging over the sides so that it can be used to pull the blondie brownie out of the baking pan.

  Set the pan aside.

Dry Ingredients:

• In a medium size bowl, add flour, baking powder, baking soda and salt. Whisk together and set aside.

For the Batter:

• Butter - In a large microwavable bowl, add the butter (3/4 cup of solid/chilled butter). *

  *Solid/chilled butter is used in this recipe so that when the butter is warmed in the microwave for 30 to 40 seconds, it gets just warm enough to melt but not get hot.  

  This should prevent the beaten eggs from curdling when added to the melted butter and sugar mixture.
• Cover the bowl with a paper towel and in a microwave, melt the butter* (about 30 to 40 seconds depending on how cold the butter is).

  * Make sure the butter does not get hot. Just let it get warm long enough for the butter to melt.

  After melting the butter in the microwave, if there are a few small pieces of unmelted butter left in the dish, just stir until they melt.
• Sugar - In the large bowl with the melted butter, add brown sugar (make sure the brown sugar is packed in the measuring cup before adding it in the melted butter). Stir together.

  To the bowl, add granulated sugar and stir until incorporated.
• Eggs and Vanilla - To the butter and sugar mixture, add lightly beaten eggs and vanilla extract.

  Beat with a hand or stand mixer until smooth.
• Add Dry Ingredients - To the butter mixture, add a couple large spoonfuls of the dry ingredients. Use the slowest setting on a mixer to mix in the flour.

  Then repeat until all of the flour has been added and mixed in to form the batter.
• White Chips and Macadamia Nuts - To the batter, add the white chips and macadamia nuts. Using a large spoon, mix the batter so that the chips and nuts are evenly dispersed.
• Biscoff Cookie Butter - To the batter, add Biscoff cookie butter. Using a spatula, fold the cookie butter into the batter creating a “swirl” pattern.

For the Batter in the Pan:

• Add the blondie batter to the baking pan. Use a spatula to spread the batter out evenly in the pan.

  On top of the batter that's in the pan, evenly sprinkle more white chips and use a spatula to lightly press them into the batter.

Bake:

• Bake in a preheated oven (at 350 degrees F.) until the edges of the blondies start to turn golden brown and pull away from the inside edges of the pan (32 minutes or very close to that time).

Cool:

• Remove the pan from the oven onto a baking rack and let the blondies cool completely while still in the pan before cutting them.

Cut:

• After the blondies have cooled completely, using the parchment paper "handles", carefully lift the blondies out of the pan and onto a large cutting board.

  Keep the blondies on the parchment paper for cutting.

  Then cut the blondies into the desired number of squares (servings).
• Since these blondies are quite rich, cutting them into either 12 or 16 squares (servings) works out nicely.

How to Cut 12 Servings:

• To cut the blondies into 12 squares, start by making a cut in the middle from top to bottom. Then make a cut that's in the middle of the left edge and the initial cut. And make a cut that's in the middle of the right edge and the initial cut.
• Next, turn the blondies around to an edge that hasn't been cut yet. Make 2 cuts from top to bottom that are equal in distance from one another and from the left and right edges.

  There should be 4 rows of 3 blondie squares, or 3 rows of 4 squares depending on the side you're looking at (12 servings).

How to Cut 16 Servings:

• To cut the blondies into 16 squares, start by making a cut in the middle from top to bottom. Then make a cut that's in the middle of the left edge and the initial cut. And make a cut that's in the middle of the right edge and the initial cut.
• Turn the blondies around to an edge that hasn't been cut yet. Make a cut in the middle from top to bottom. Repeat the same cutting pattern to the left and right of the initial middle cut as before.

  There should be 4 rows of 4 blondie squares (16 servings).

Serve:

• Serve these blondie brownies as a finger food or with a fork.