Molasses can occasionally be obtained from cold-loving creatures like Rambeaus, Arctic Mirus and/or Blizzard Chizzards, either as a "drop" in their Loot Bags after you've killed them, or as a harvest from them after you've tamed them to make them your Pets and have fed them their favorite Food. Molasses can also be found in Holiday Gifts, however only during the christmas-holiday season.
Molasses is a non-flammable thick liquid that flows down really slowly and can only expand onto the surrounding 4 blocks when being placed, unlike Water and most other Liquids that will spread up to 3 blocks horizontally and 2 blocks diagonally.
Like all the other Liquids in Creativerse you can multiply Molasses "infinitely" too. To do so it's best to let it flow downwards and scoop up blocks from further down, then to wait a little until more has dropped down and has filled the gap. You will not need to equip any kind of Power Cells to forage Molasses.
Molasses can be used as a liquid ingredient to make Gingerbread Loaf in the Cooking Station by using the basic cooking recipe for Bread. This recipe is unlocked in the Cooking Station when harvesting Wheat - that can be grown on tilled land close to Water from Wheat Seeds that can be obtained occasionally when harvesting Tallgrass or Savannah Tallgrass.
Gingerbread Loaf can then be used as a crafting-ingredient for a few christmas-building-blocks, as long as the rare crafting-recipes for these have been unlocked in your crafting menu. The recipes are a rare finding in Holiday Gifts during christmas season, but some left-over recipes for these special blocks might still be owned and given to you by players who played the game throughout the holiday-season.