Preheat your oven to 350°F (175°C). Grease and flour a cake pan.
Wash and finely chop the okra. You can sauté it lightly in a pan for a few minutes to reduce moisture, then set aside to cool.
In a bowl, combine almond flour, all-purpose flour, baking powder, and salt. Mix well and set aside.
In another bowl, cream the softened butter and sugar together until light and fluffy. This should take about 3-4 minutes.
Beat in the eggs one at a time, followed by the vanilla extract. Mix until well combined.
Gradually add the dry ingredients to the wet mixture, mixing just until incorporated. Fold in the chopped okra and walnuts gently.
Pour the batter into the prepared cake pan and smooth the top. Bake for 25-30 minutes, or until a toothpick inserted into the center comes out clean. Let it cool before serving, and dust with powdered sugar if desired.