Preheat oven to 425°.
Place the squash halves on a baking sheet with the scooped out sides facing up. Divide the butter and maple syrup between the halves. Add the bourbon now too, if using.
Bake until tender, about 45-50 minutes, basting the insides of the squash with the butter and syrup a couple of times.
With about 10 minutes left in the baking cycle, add the pecans (and the pre-cooked bacon, if using).
Return to the oven for about 10 more minutes, until edges of squash are golden, and start to char just slightly.
Carefully remove from the oven to avoid splashing hot maple syrup on yourself! Allow to cool slightly before serving.
To eat, use your fork to gently pull the softened squash away from the skin, fluffing and mixing with the syrupy goodness in the middle.