Preheat the oven to 350F (325F convection). Butter and flour a bundt pan.
Boil the almonds in water for 2 minutes and drain. Pop them out of their skin. In the blender jar put in the five eggs, then add the blanched almonds. Blend on high for about 5 minutes or until you have a silky smooth paste.
Sift together the cake flour and baking powder.
Cream the butter and sugar till light and fluffy. Add the vanilla extract and orange zest. Add the almond paste mixture and blend well. Add the flour mixture, poppy seeds, and stir well.
Scrape the mixture into the prepared bundt pan and smooth over the top. Put in the oven for 40 - 45 minutes. Check by inserting a butter knife near the center, it should come out almost clean. Wait at least 10 minutes before inverting it out of the pan.
Optional: mix about a quarter cup of lemon or orange juice with ¾ cup confectioner’s sugar and glaze the warm cake with it.