Preheat oven to 170°C (convention)/150°C (fan-forced/convection).
Grease and line an 7-inch (base diameter) shallow cake tin with baking paper. (I grease it with olive oil and dust it generously with polenta, instead of lining with baking paper).
Place almond meal, polenta, baking powder, salt, lemon zest, olive oil, maple syrup, sugar and eggs in a large bowl. Mix well using a wooden spoon.
Scrape batter into the prepared tin.
Place jam in a small microwave safe bowl and warm it for 20 seconds to loosen it.
Drop dollops of jam evenly over the cake batter. Using a wooden chopstick or skewer, swirl the jam around gently over the batter.
Bake in the preheated oven for approximately 40 minutes until the top is springy to touch (make sure you don’t poke your finger in the hot jam when you check). Turn off the oven. Let the cake sit in the warm oven for 5 minutes. Remove from the oven and cool completely in the tin. Slice and enjoy with fresh cream or as is.
It is important to use a smaller tin (7-inch base diameter) in this recipe as the quantity isn't a whole lot and if you use a bigger tin, you won't get any height to the cake. My tin is 7 inch wide and just less than 2 inches tall.