Preheat your oven to 400 degrees Fahrenheit and line a baking sheet with parchment paper.

Rinse the squash and pop off the stem. To make the squash easier to cut, microwave it for 2 minutes to soften it and allow it to cool for a minute. Use a large sharp knife to slice the squash in half, lengthwise. Pierce it in the center of a depression line, then cut through, following the line of the ridge. Use a large spoon to scoop out the seeds and pulp. Lightly score the flesh of the squash to allow the cinnamon butter to absorb better, don't cut too deep or you might cut through. Place the squash halves cut side up on the parchment-lined baking sheet.

To make the cinnamon butter, in a small bowl, combine the softened butter, cinnamon, brown sugar, and salt by mixing and mashing with a fork. Spoon the cinnamon brown sugar butter equally into the squash cavities and spread to coat all of the flesh, including the top.

Place the baking sheet onto the center rack of your preheated oven. Bake the squash until the flesh is soft, about 35 to 45 minutes, depending on the size of your squash. My squash was perfect at 40 minutes, pierce with a fork to check for doneness. Once your squash has finished baking, carefully remove it from the oven and serve warm.