Easton had been acting as caretaker manager following the departure of Chris Rawlinson by mutual consent following the 1-0 defeat to Brantham Athletic on September 8.
The Tulips have drawn all three of their games under Easton so far, including Tuesday night’s penalty shoot-out defeat to Belper Town in the Integro League Cup.
A club statement said: “The board were not short of credible applications for the long-term manager's role but they felt that Matt had earned his chance, had full respect/command of the changing-room and was very much his own man in terms of developing an entertaining style of play which supporters want to see.
“The club would like to formally welcome Matt in his new permanent post and we're sure everyone in Tulipsville wishes him and his backroom team of Lewis Thorogood, Bob Don-Duncan and Richard Storey all the very best going forward.”
Spalding take on EVO-STIK East league leaders Ossett United away on Saturday, before another away date with local rivals Stamford on Tuesday.
Keep up-to-date with our exclusive email newsletters.
Subscribe