Step 1

In a small sauce pan over medium heat, add the rhubarb, the water, and 2 tablespoons of the granulated sugar, stirring to combine.

Step 2

Bring the mixture to a boil.

Step 3

Once the sugar is dissolved, lower the heat to a simmer and cook until the rhubarb is soft, about 10 minutes.

Step 4

Transfer the rhubarb mixture from the stovetop to a wire rack and let it cool slightly.

Step 5

Transfer the slightly cooled rhubarb mixture to a blender and purée until smooth.

Step 6

Preheat the oven to 350 degrees F.

Step 7

Spray the bottom and sides of an 8x8x2-inch baking dish with non-stick cooking spray.

Step 8

Line the bottom of the baking dish with parchment paper and spray the parchment paper with non-stick cooking spray. Allow the parchment paper a couple inches of overhang on the sides to help get the brownies out later.

Step 9

In a medium bowl, add the flour, the baking powder, the New Mexico chile powder, the cinnamon, and the kosher salt and sift to combine.

Step 10

In a clean microwavable glass bowl, add the bittersweet chocolate and the unsweetened chocolate.

Step 11

Place the bowl in a microwave at 50% power and cook, stirring intermittently, until melted and smooth, about 30 seconds-1 minute.

Step 12

In a large bowl with a stand mixer on medium speed, add the butter and the remaining sugar and cream together until well-blended.

Step 13

One at a time, add the eggs to the butter mixture and beat to combine.

Step 14

Add the vanilla and the dark rum to the butter mixture and beat to combine.

Step 15

Transfer the rhubarb compote to the melted chocolate mixture and stir to combine.

Step 16

Transfer the rhubarb-chocolate mixture to the butter mixture and mix until combined.

Step 17

Add the flour mixture to the butter mixture and mix until just combined.

Step 18

With a rubber spatula, scrape down the sides of the bowl with the batter and add the semisweet chocolate chips and the walnuts. Gently fold to combine, being careful not to over mix.

Step 19

Evenly transfer the batter to the bottom of the prepared baking dish.

Step 20

Bake, uncovered, until a toothpick inserted into the center comes out clean, about 35-40 minutes.

Step 21

Transfer from the oven to a wire rack and let cool.

Step 22

When the brownies are cool, with a sharp knife, cut them into serving-size pieces.

Step 23

Plate and serve.