Chromatic Blade

You summon arcane energy to form into a dagger in your hand. Choose a damage type from; Cold, Fire, Acid, Poison, Radiant, Necrotic, Thunder or Lightning. This blade is made from this element. The blade will last for 1 minute unless you release your grip on it, in which case it disappears. You can use your action to make a melee weapon attack using the chromatic energy, you can use your spellcasting ability instead of Dexterity for the attack and damage rolls, but exchange the damage with the chosen elemental type. 

The spell's damage increases by 1d4 when you reach 5th level (2d4), 11th level (3d4), and 17th level (4d4).