Lunging Spell Touch

You can extend your spells’ reach to affect foes that would normally be too far away.

Prerequisite: Spellcraft 6 ranks.

Benefit: As a free action, you can increase the reach of your spells’ melee touch attacks by 5 feet until the end of your turn by taking a –2 penalty to your AC until the start of your next turn. You must decide to use this ability before you make any attacks on your turn.

Source: Advanced Class Guide