Are there records in Medieval European literature, (hagiographic literature, chronicles, legal records and philosophical treatises. etc..), of supernatural events attributed to God or particularly saintly individuals? This can include acts that have later been interpreted as natural phenomena as well as any that defy a clear explanation.
Guibert de Nogent's works are a good example: he was born to minor nobility in Clermont in modern northern France in the 1150's and lived almost 75 years. He wrote an autobiography De vita sua sive monodiarum suarum libri tres which is often referred to by medievalists as one of the first 'personal works' of the high middle ages. Guibert was an abbot, a prolific writer, and many personalities and events of the late 11th-early 12th century appear in his works.
I recommend the recent Penguin books edition of De vita translated by Jay Rubenstein, Monodies and On the Relics of Saints: the Autobiography and a Manifesto of a French Monk from the Time of the Crusades (2011). Included in this work is Guibert's Treatise on Relics which is a fascinating view on sainthood, miracles and relics in the first part of the high middle ages; Fordham has an extract from an older translation here.
In this you'll find plenty of works and interventions of God and the Virgin Mary, as well as some other spirits and demons.