Steven Mullaney hailed Nottinghamshire's positive intent on the day he scored his 16th first-class hundred and passed 8,000 career runs.
The captain added to his overnight half-century with Lyndon James, who himself scored 51, Liam Patterson-White and Stuart Broad as Notts finished 224 ahead after the first innings.
James struck to dismiss Alastair Cook as the visitors inched towards parity, before Broad induced an edge from Tom Westley and Dane Paterson rocked Dan Lawrence's off-stump to leave Essex 129 for three at the end of day two, 95 runs behind.