Preheat the oven to 350 degrees F., and spray a bundt pan with nonstick spray or nonstick baking spray with flour.
MAKE THE CAKE BATTER:
Sift the cake mix into a small bowl to remove any lumps. Add the pudding mix and whisk together. In a large bowl, combine the eggs, oil, milk, zest, juice and yogurt. Add the dry mixture and stir well.
MAKE THE RASPBERRY SWIRL:
In a blender, puree the raspberries and sugar. Press through a sieve to remove the seeds and discard. Mix 3 tablespoons of the cake batter with the raspberry juice.
BAKE THE CAKE:
Pour ½ of the cake batter into the prepared pan and spread evenly. Pour the raspberry swirl over the cake batter and spread around evenly. Spoon the remaining batter over the raspberry layer and spread to cover evenly. Bake 40 to 55 minutes, or until a knife inserted near the center come out clean. Let the cake cool in the pan, then turn out on a cooling rack to cool completely.
ADD THE LEMON GLAZE:
In a medium bowl, whisk together the butter, lemon juice and powdered sugar until smooth. Add more powdered sugar to make the glaze thicker or more lemon juice to make it thinner. Pour the glaze decoratively over the cake. Serve with fresh raspberries.