Preheat oven to 350 degrees; grease a Bundt pan with butter and dust lightly with flour.
Using a stand or hand mixer, combine butter and sugar until light and fluffy.
Add eggs to mixture one at a time and beat until well combined; add in vanilla, buttermilk and orange juice.
Sift together flour, baking powder, baking soda, and salt and then add to the wet ingredients, continuing to mix to combine all ingredients. Stir in poppyseeds.
Pour batter into Bundt pan and bake for 45-50 minutes. Let it cool slightly before inverting and removing from the pan.
To make the glaze: combine sugar, orange juice and zest, butter, and vanilla in a bowl, whisk together until smooth.
While cake is still warm, pour the glaze over the top and garnish with additional poppyseeds, let it cool before serving.
Recipe by DomestikatedLife at https://domestikatedlife.com/2023/04/04/orange-poppyseed-bundt-cake/