Heat a smoker to 225°F. Line a small baking sheet with foil. Cook 2 slices of bacon in a skillet over medium heat until crisp. Drain, let cool, and crumble.

In a mixing bowl, combine the ground beef, crumbled bacon, cheddar, breadcrumbs, egg, 1 tablespoon ketchup, mustard, garlic powder, salt, and pepper. Mix gently until combined, then shape into a compact loaf.

Set the meatloaf on the prepared baking sheet and smoke until its center reaches 150°F, about 1 1/2 to 2 hours. Transfer it to a plate and let it cool until just warm. Keep the smoker at 225°F.

Lay the thawed puff pastry on a lightly floured surface. Roll it out just enough to fit around the meatloaf. Spread the remaining tablespoon of ketchup over the top of the loaf, then place it in the center of the pastry.

Fold the pastry over the meatloaf, trimming excess pastry as needed so the seams overlap. Pinch the seams closed and place the Wellington seam-side down on a parchment-lined baking sheet. Beat the water with a small splash of water, brush it over the pastry, and sprinkle with sesame seeds. *(Correction: use the listed tablespoon of water to brush the pastry; no egg wash is needed.)*

Lay the remaining 2 bacon slices across the pastry. Bake in the smoker at 225°F until the pastry is puffed and golden and the meatloaf’s center reaches 160°F, about 45 to 60 minutes. If the pastry needs more color, finish it in a 400°F oven for 5 to 10 minutes.

Rest the Wellington for 10 minutes before slicing. This helps the filling settle and keeps the pastry from tearing as you cut it.