Minecraft wiki entry for Stone_Bricks, associated text: When smelting cobblestone blocks, the cracked form of stone, they turn into stone without cracks. Yet, when smelting stone bricks without cracks, they turn into a cracked variant.
On Bedrock Edition, there is an unused data value for stone bricks called smooth stone bricks, it can be obtained through commands but is unobtainable in survival mode or through the creative inventory.