Preheat oven to 350 degrees F (175 degrees C). Line a baking sheet with parchment paper.
Heat 1 tablespoon olive oil in a large skillet over medium heat. Add pine nuts; cook and stir until lightly toasted, about 2 minutes. Transfer to a paper towel-lined plate with a slotted spoon.
Heat remaining 1 tablespoon olive oil in the same skillet over medium heat. Add beef; cook, stirring to break up clumps, until no longer pink, 3 to 5 minutes. Stir in onion; cook and stir until tender, 3 to 5 minutes. Remove from heat; season with cinnamon, allspice, salt, and pepper. Stir in pine nuts.
Cut each spring roll wrapper into three 12x4-inch rectangles. Brush each rectangle lightly with melted butter.
Place a heaping teaspoonful of the beef mixture near the short end of 1 rectangle. Fold 1 corner over to enclose the filling and form a triangle. Continue to fold until the rectangle has been folded into a triangular packet, sealing any holes to prevent filling from oozing out. Dab cold water on the outside fold to seal sambusa closed.
Repeat with remaining spring roll rectangles and beef mixture. Arrange sambusa on the prepared baking sheet.
Bake in the preheated oven until crisp and golden, about 25 minutes.
The spring roll wrappers in Asian supermarkets are best. If spring roll wrappers are frozen, remove from freezer and allow to thaw for 2 hours in fridge or 30 minutes at room temperature. Make sure they are still in the package, as they will dry out.
You can also use milk or beaten egg white to seal the edges of the wrappers.
Traditionally, sambusa are deep fried. Cook in hot oil, several at a time, until golden and bubbly. Remove and drain on a paper towel.