It is not my recipe, someone who teaches food technology at a school in UK. It is delicious, I made it last week, even better when made as a sandwich with a jam filling.
Fat content is about 4 gm. per large egg, 3 eggs=12gm. The recipe makes a 7-8 inch cake, which gives you about 6-8 slices, so only 1.5gm. roughly per slice.
Eggs are the raising and setting agent... you could remove them and start a chemical soup going but would you want to replace that bit of fat with lots of chemicals ?
Steve