Butter tart bars are a rich and indulgent dessert inspired by the classic Canadian butter tart. They feature a tender, buttery shortbread crust topped with a gooey, caramel-like filling made from brown sugar, butter, eggs, and a hint of vanilla. The filling is soft and slightly chewy, with a sweet, almost toffee-like flavor. Some variations include raisins or chopped pecans for added texture and depth. Once baked and cooled, these bars are sliced into squares for an irresistible treat that's both nostalgic and decadently satisfying.