Preheat your oven to 200C / 400F (fan off), 180C / 350F (fan on). Spray a 9 x 13-inch/22 x 33cm tin with oil spray and line the bottom and sides with baking paper.
Mix dry ingredients - To a large mixing bowl add the flour, breadcrumbs, baking powder, bicarb soda, cinnamon, cloves and salt and whisk to combine.
Cream sugar and butter - To a separate bowl add the butter and sugar and beat on high-speed using an electric hand mixer for about 3 minutes until pale and fluffy.
Add eggs - Scrape down the bowl and add the eggs one at a time, beating each time.
Finish batter - Add half the dry ingredients, half the milk and all of the Frangelico to the butter and egg mixture and use a spatula to mix until well combined. Add the remaining dry ingredients, milk and all of the walnuts and mix until combined.
Bake - Add to the cake tin and use a spatula to spread evenly. Bake in the middle rack of your oven for 25-30 minutes. Once baked, allow to cool completely.
Syrup
Boil syrup - Add all of the ingredients to a large pot and bring to a boil on high heat. Continue boiling for 5 minutes.
Pour over cooled cake - Pour the hot syrup over the cooled cake. Place in the fridge to chill for 3 hours or overnight. Slice in diamond shapes or squares and sprinkle with some crushed walnuts. Serve.
Notes
Breadcrumbs - I used store bought, fine breadcrumbs. I wouldn’t recommend using panko or fresh breadcrumbs.Storage - Karithopita can be stored in an airtight container for up to three days.Nutrition – is an approximate and is based on per slice. This recipe makes 24 slicesA note on measurements – This recipe uses weight measurements for the most accurate results. Cup measurements can vary depending on where you are, which affects the precision needed for a recipe like this. Here is where you can learn more about how to measure ingredients using digital kitchen scales.