Brimstock's Burning Barrow

A circle of flaming embers 20 feet wide emanates from you. Each creature of your choosing in the area must make a Dexterity saving throw. A creature also makes this save when the spell’s area moves into its space and when it enters the spell’s area or ends its turn there. A creature makes this save only once per turn. A creature takes 3d6 fire damage on a failed save, or half as much damage on a successful one. 

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the damage increases by 2d6 for each slot level above 1st.