It wasn't my fault, honest!
Turned to the recipe for Black Bread - rye based, coloured with cocoa and coffee. All went well, followed the recipe to the letter, since I hadn't made it before. Added the 300g of melted butter. . . well, that turned out to be a misprint. The mix went totally soggy. I see my recipe book now has a note - 30g in pencil and underlined. I baked it anyway, and it was awful.
Then there's my first fatless sponge cake. There I didn't understand the instructions about beating the egg yolks. . . flatter than pancakes resulted and even the chickens wouldn't touch it.