In a large bowl, gently mix the crab meat, mayonnaise, mozzarella, cheddar, green onions, parsley, lemon juice, and Worcestershire sauce. Season with salt and pepper to taste. Use a spatula to combine without breaking up the crab too much.
Cover the bowl and refrigerate for at least 30 minutes to let the flavors meld and the mixture firm up slightly.
Preheat the oven to 375°F (190°C). Line a baking sheet with parchment or lightly grease it.
Slice the bread in half lengthwise and place both halves cut-side up on the baking sheet.
In a small bowl, mix the melted butter and minced garlic. Brush the garlic butter generously over the cut sides of the bread.
Spread the chilled crab mixture evenly over the two bread halves, pressing lightly so it adheres.
Bake for 20–25 minutes, until the cheese is melted, bubbly, and the edges of the bread are golden brown.
Remove from the oven, cool for 3–5 minutes, slice into pieces, and serve warm.
Notes
Use fresh lump crab for the best texture; chill the crab mixture for better spreadability; avoid overbaking.