This is a timeline in which the major POD is that the Treaty of Westphalia never ocurred. The Thirty Years War became the Forty Years War, dragging on until peace was reached in 1659 between France and Spain, with very different results.
Continuation of War in 1648
Cardinal Mazarin, the regent in France, foiled attempts at peace by Austria in 1648. Determined to destroy Spanish influence on the continent, he negotiated alliances with the three major German principalities: Brandenburg, Bavaria and Saxony. He also secured a treaty from the Dutch Republic in order to partition the Spanish Netherlands.
Philip IV of Spain responded by initiating a vast invasion of France in 1649, from the Netherlands, Aragon, Lombardy and Burgundy. Franco-Dutch troops crushed the Spanish Army of Flanders at the Battle of Cambrai in December, and launched a counter offensive against Besancon in Spanish Burgundy. Spain also failed to make headway against the Pyrenees.
In January 1649, Brandenburg invaded Silesia. The province had been completely occupied by 1650. Austria simultaneously suffered humiliating defeats in the Netherlands. In 1653, Austria concluded peace with France. Silesia would be ceded to Brandenburg, and Emperor Ferdinand would withdraw support for the Spanish Emperor, but in a secret agreement, Lombardy and the Venetian Republic were promised to Austria after the fall of Spain. Austria honoured their side of the agreement and would invade the Kingdom of the Two Sicilies in 1655.
End of the Eighty Years War
By 1653, France had overrun the Spanish Netherlands. Marshal Turenne had inflicted decisive defeats on Spain at Besancon (1649), Cambrai (1649), Flanders (1650), and Mons (1652). On 5th of March, 1653, Spain recognised the Dutch republic and ceded the Southern Netherlands, which were partitioned between France and the United Provinces. Turenne now invaded the Holy Roman Empire.