Preheat smoker to 275ºF.

In a large bowl, melt the butter before stirring in the brown sugar. Add the walnuts to the butter mixture and stir to evenly coat.

Add the coated walnuts to a parchment covered sheet pan or disposable foil pan with a wire rack. Grates will help the walnuts pick up more smoke.

Smoke for 1 hour. Let the walnuts cool completely before incorporating into the brownie batter.

Increase the Traeger temperature to 375ºF.

In a large mixing bowl, whisk together the olive oil, vanilla, sugar and light brown sugar.

Add the lightly beaten eggs and whisk in until completely combined.

Add the cocoa powder, instant coffee powder, salt, and flour. Mix until combined.

Gently fold in the smoked walnuts until evenly dispersed throughout the batter.

Pour the batter into a 9 x 13 baking dish. Place in the Traeger and cook for 40-45 minutes or until a toothpick inserted comes out clean.