Pre-heat oven to 325 degrees. Take out all ingredients ahead of time so they are at room temperature. Butter the bundt cake pan.
Beat butter for about a minute on medium speed. Add in sugar and beat for a few more minutes until combined and fluffy. Beat in egg yolks one at a time until combined. Beat in vanilla until combined. Slowly add in flour and beat on slow until combined.
In a new bowl combine egg whites, cream of tartar, and salt. Beat with whisk attachment on medium-high speed until stiff peaks form.
Once stiff peaks form fold in 1/3 of whites into batter. Once combined fold in rest of egg whites.
Once completely combined pour into greased bundt pan and put in oven for 1 hour or until toothpick comes out clean. Cool on a wire rack for about an hour before serving.
To make whipped cream in a clean bowl beat heavy whipping cream and powdered sugar on high speed with whisk attachment. Whip to stiff peaks.
Once cake is cooled top with whipped cream, fresh blueberries, and a sprinkling of powdered sugar.