Upcasting - doombubbles/DoombubblesTweaks GitHub Wiki

Shield - Upcasts now give +1 more AC per additional spell slot level

Divine Favour - Upcasting at 3rd or 4th level increases bonus to +2d4, 5th and 6th to +3d4

Goodberry - Now creates 1 additional Berry per additional spell slot level

Thunderous Smite - Now deals an extra 1d6 damage per additional spell slot level

Witch Bolt - Subsequent activations now also deal an additional 1d12 damage per spell slot level

Wrathful Smite - Now deals an extra 1d6 damage per additional spell slot level

Blinding Smite - Now deals an extra 1d8 damage per additional spell slot level

Many cantrips can now be upcasted to be stronger but actually cost a spell slot.

Fire Bolt - Deals 3d10 Fire damage for 1st level, up to 8d10 Fire damage for 6th level.

Eldritch Blast - Shoots 3 beams for 1st level, up to 8 beams for 6th level.

Ray of Frost - Deals 3d8 Cold damage for 1st level, up to 8d8 Cold damage for 6th level.

Bone Chill - Deals 3d8 Necrotic damage for 1st level, up to 8d8 Necrotic damage for 6th level.

Shocking Grasp - Deals 4d8 Lightning damage for 1st level, up to 9d8 Lightning damage for 6th level.

For cantrips that do no damage on a successful saving throw, their upcasted versions deal half damage on a sucessful saving throw.

Sacred Flame - Deals 4d8 Radiant damage for 1st level, up to 9d6 Radiant damage for 6th level.

Vicious Mockery - Deals 4d6 Psychic damage for 1st level, up to 9d6 Psychic damage for 6th level.

Acid Splash - Deals 3d6 Acid damage for 1st level, up to 13d6 Acid damage for 6th level.

Poison Spray - Deals 3d12 Poison damage for 1st level, up to 8d12 Poison damage for 6th level.

Thorn Whip - Deals 4d6 Piercing damage for 1st level, up to 9d6 Piercing damage for 6th level

Other

Shillelagh - 2d8 damage at 1st and 2nd level, 3d8 at 3rd and 4th, 4d8 at 5th and 6th