Preheat the oven to 250 degrees F. Unwrap the ham and place it on a large rimmed baking sheet. Place the apricot preserves, crushed pineapple, and dijon mustard in a microwave safe bowl. Warm in the microwave for 2-3 minutes, until the apricot preserves soften enough to mix evenly into the other ingredients. Stir well.
Brush half the apricot glaze over the surface of the ham. Open and separate the slices here and there to let the glaze seep down between the layers as you brush it. Cover the ham with foil and place it in the oven for 2 hours.
Meanwhile, roughly chop (or crumble) the sliced almonds into smaller pieces. (This helps them stick to the edges of each slice of ham.) Toss the almond pieces with the brown sugar.
After 2 hours, remove the ham from the oven and raise the temperature to 400 degrees F. Brush the remaining glaze over the ham. Then press the almond and brown sugar mixture over the entire surface of the ham. Place it back in the oven for 30 minutes, uncovered, to allow the almond crust to brown. Serve warm.
NOTE: All brand names mentioned in this recipe come from ALDI.