For the roasted garlic: Preheat the oven to 375 degrees F.
Place the olive oil and garlic in a ramekin or small baking dish and roast, making sure the garlic does not begin to brown but just turns a light golden color and becomes tender, 15 to 20 minutes.
For the hummus: Add the roasted garlic cloves plus 2 tablespoons of the oil from the ramekin (reserve the remaining oil) to a food processor along with the garbanzo beans, pumpkin puree, lemon juice, tahini, pumpkin pie spice and a nice pinch of salt. Blend until smooth, then add a bit more of the roasted garlic oil to smooth out the texture. Taste and add a bit more salt and lemon juice if needed. Spoon into a bowl and pour any remaining olive oil over the top; cover and refrigerate at least 2 hours.
For the pumpkin seed garnish: When ready to serve, add the pumpkin seeds and a pinch of salt to a saute pan on medium-high heat and toast, tossing, until the seeds are fragrant and develop a bit of a sheen, about 4 minutes. Season with a pinch of salt.
Sprinkle the toasted pumpkin seeds over top of the hummus and serve slightly chilled or at room temperature.