Zest and peel the oranges.

Use small sharp knife to trim off as much of the pith (white part) as you can.

Cut oranges with a serrated knife into slices about 1⁄4 inch thick and set aside.

Make the streusel:

Whisk together the flour, sugar, and salt.

Add the butter, olive oil and orange zest to the bowl.

Use your fingers or a wooden spoon to rub the butter and oil into the dry ingredients until streusel crumbs form.

Cover the bowl with plastic cling film and refrigerate for 30 minutes.

Make the cake:

Preheat oven to 375 F. Grease and line a 9x13 baking pan with parchment paper. Set aside.

In a separate bowl, whisk together the flour, cornstarch, baking powder, cardamom, and salt.

Beat the butter and sugar with the whisk attachment of your mixer until light and creamy (5 minutes)

Add the eggs one at a time making sure each is combined before adding the next.

Mix in the marzipan and almonds.

Add the rest of the orange zest.

Add the dry ingredients and beat until just combined.

Spread the dough evenly on the prepared baking pan.

Distribute the orange slices evenly spaced over the top.

Do the same with the streusel.

Place in oven and bake for 50 minutes or until a knife inserted in the middle of the cake comes out clean.

Remove the oven, let cool, slice, and serve.