Bake the salmon. Preheat the oven to 425°F. Line two large baking sheets with parchment paper, and set one baking sheet aside for later. Place the large piece of salmon on top of one of the baking sheets. Blot the salmon with a paper towel to remove any excess moisture. Drizzle the salmon with a tablespoon of olive oil and generously season with salt and black pepper. Cook for 10 to 12 minutes, or until it reaches an internal temperature of 145°F. Lower the temperature to 400°F.
Cool baked salmon. Remove the salmon from the oven and cool completely in the refrigerator for 10 minutes.
Sauté the vegetables. In a large frying pan or skillet, add one tablespoon of oil, the diced onion, and red bell pepper. Sauté on medium-high heat for 6 to 8 minutes, or until soft and translucent. Remove from the heat and let cool.
Combine ingredients. Once the salmon and vegetables have cooled, use your hands to flake the cooled salmon breaking it up into small pieces (removing the skin and tiny bones) into a large mixing bowl. Add the onion, bell pepper, freshly chopped dill, parsley, mayonnaise, Dijon mustard, minced garlic, almond flour, whisked eggs, salt and black pepper. Stir the mixture until everything is well combined.
Form the patties. Use a large cookie scoop, to portion 12 equal-sized salmon patties. Carefully mold each patty into a round ball with your hands and place the 12 patties onto the other parchment-lined baking sheet. Slightly flatten each salmon patty with your hands by pressing down on the top and molding the sides if needed.
Bake the patties. Place the baking tray in the oven at 400°F for 20-22 minutes, on until the bottoms are golden brown. Allow the salmon cakes to cool for 5 minutes before serving.
Make the lemon dill crème fraîche sauce (optional). Add the crème fraîche, chopped dill, lemon zest, lemon juice, minced garlic, capers, and black pepper to a small mixing bowl and stir to combine.