Britain and France had the distinction of gaining empires, losing empires and then gaining new ones.
Britain lost its most populous and important overseas imperial territory in 1783, but got back on its heels and claimed an even larger and more populous empire from 1788 (with settling Australia) with gradually increasing speed through the 19th century till the 1880-1919 era where it seemed on a mad quest to color the map pink.
France lost its largest, if not most populous or profitable, overseas possessions 20 years earlier, in 1763, yielding its North American territory to Britain and Spain.
The French Revolutionary and Napoleonic era featured an interlude of attempted empire-building on the European continent. But with the conquest of Algeria in 1830, then with gradually increasing speed through the 19th century till the 1880-1919 era where it seemed on a mad quest the color the map pink.
Your challenge, if you choose to accept it, is much bigger 2nd empires for Spain and the Netherlands:
OTL, Spain, after losing Spanish America, gained only Rio Muni and parts of Morocco for its rather third-rate overseas empire.
How could Spain have taken over larger, more important or more populous territories after 1830?
OTL the Netherlands, after losing the Cape, kept losing African territories and never made a second empire, except for fleshing out the DEI.
How could the Netherlands have taken over larger, more important or more populous territories after 1815?