Relatively common in Finland to use young nettles like you’d use spinach in hot dishes (soup, blanched, pancakes).
Is this a frittata-style baked pancake? I've made rye pannukakku from the family cookbook here in the US Midwest but never seen any Finnish pancake with spinach or nettle.
https://scandicuisine.com/stinging-nettle-pancakes/ looks quite reasonable though most Finns would not use a blender for this.