Poppy seed Buttermilk Cake

1/2 cup poppy seeds
1 cup buttermilk
1 cup butter
1 cup white sugar
4 eggs
1 teaspoon vanilla extract
2 1/2 cups all-purpose flour
1 teaspoon baking soda
1/2 teaspoon salt
1 1/2 tablespoons ground cinnamon
1/2 cup white sugar

Soak poppy seed in buttermilk for 6 to 8 hours or overnight.
Preheat oven to 350 degrees F (175 degrees C), grease a 10 inch bundt pan. Mix together cinnamon and 1/2 cup sugar. Sprinkle part of the cinnamon sugar mixture evenly over greased pan. This will form a thin crust over the cake. Set aside the remaining cinnamon sugar mixture.
Cream butter and 1 cup sugar until light and fluffy. Add eggs one at a time, beating well after each addition. Add vanilla.
Sift flour, salt and soda together. Add to butter mixture alternately with the poppy seed mixture. Blend well.
Put the batter in the pan in layers, sprinkling the reserved cinnamon sugar mixture between each layer. If you spread your batter thin, you should get three layers of cinnamon sugar. (I only had one layer of cinnamon in the middle and sprinkled the rest at the end so both top and bottom of the cake has cinnamon-sugar)
Bake at 350 degrees F (175 degrees C) for 40-50 minutes or until a toothpick inserted comes out clean. Set cake on rack to cool for one hour. Goes well with whipping cream or plain by itself!