I generally view blessing as something coming from a superior to an inferior
yea, theres a verse…
Hebrews 7:7 But without any dispute the lesser is blessed by the greater
but then David blesses the LORD lots of times in the Psalms (bless the LORD O my soul, etc)
actually I don’t know how that works in reverse either…sorry

But I know that I bless God in my prayers with what I have to bless him with (which relatively speaking is not much) with my thoughts of him, my praise to him, and my glorying in him. With the Holy Spirit and with Christ in us we should be able to bless him. On the other hand though it does sound kind of condescending to God if I say ‘
I am the one who blesses thee O God’ as if I could make God more blessed by my blessing him.
or maybe ‘the lesser’ blessing God is in the act of calling him blessed,

like in this verse,
John 12:13 Took branches of palm trees, and went forth to meet him, and cried, Hosanna: Blessed is the King of Israel that cometh in the name of the Lord.
interesting question