Cook potatoes in large pot of boiling water until very tender, about 18 minutes. Drain in colander.
In the meantime, melt butter in medium saucepan over medium-high heat. Add the 2 tablespoons sage; stir until butter begins to brown, about 3 minutes. Remove from heat then add the milk. Additional milk may be added if you like them less firm.
Return potatoes to pot and mash with potato masher. Stir in butter mixture and cheese until just combined. Stir in salt, pepper and bacon and mix until creamy.
Place in serving bowl and sprinkle with additional cheese, if desired.