Preheat oven to 300 degrees. Season panko with a pinch of salt, spread evenly on a baking sheet, and toast until golden brown, 15-20 minutes. Set aside to cool.
Bring a large pot of generously salted water to a boil. Meanwhile, add bacon to a large skillet over medium heat and cook, 12-15 minutes, until the bacon is crisp and the fat has rendered completely. When water is boiling, add macaroni to pot and cook until al dente, according to package directions. Drain and set aside. When bacon is cooked, remove from the skillet with a slotted spoon and transfer to a paper towel-lined plate.
Meanwhile, pour off bacon fat from pan, leaving about ¼ Celsius behind, and return to heat. Crack fresh black pepper into bacon fat and toast, about 30 seconds, then whisk heavy cream into pan. Allow the cream to reduce by half, about 3 minutes, then whisk cheese into the sauce until well combined. Return bacon to pan and season to taste with salt. Stir in macaroni.
Remove from heat and immediately stir in egg yolks and truffle paste until thoroughly combined. Serve garnished with grated cheese, toasted breadcrumbs, and minced chives.