Didn't spread, stayed mounded in cookies: what causes it?

Likely causes: Too much flour. Too little sugar or fat. Over-chilled, so the dough was too cold to relax. Too much leavening set the structure before it could spread. What to change: Reduce the flour. Rest the dough at room temperature before baking. Rebalance the sugar and fat upward.

Didn't spread, stayed mounded

4 likely causes, sorted by where the problem lives. Work down the list and change one variable at a time.

Likely causes

formulaToo much flour.
formulaToo little sugar or fat.
techniqueOver-chilled, so the dough was too cold to relax.
formulaToo much leavening set the structure before it could spread.

What to change

Reduce the flour.
Rest the dough at room temperature before baking.
Rebalance the sugar and fat upward.

Read it with the four domains in mind

FormulaThe recipe itself: ratios, quantities, and ingredient choice.

TechniqueWhat you did: mixing, shaping, timing, handling.

EnvironmentThe room: temperature, humidity, altitude, storage.

EquipmentThe gear: oven calibration, pans, mixer, tools.

Adapted from the master symptom matrices in Environmental Variables & Troubleshooting. General sourcing across these tables: Figoni (2011); Gisslen (2016); Corriher (2008); McGee (2004); Modernist Bread (2017); King Arthur Baking technical guides; BAKERpedia.

Other cookies symptoms

Spread too much, came out thin Cakey when you wanted chewy Tough Burnt or over-browned bottoms Uneven baking or browning across the sheet

Cookies, Macarons & Petits Fours · The full troubleshooting method · All 50 symptoms