Preheat oven to 350. Grease and flour a 12 cup or 10 inch tube. In the microwave, place 3/4 cup preserves and put on about 45 seconds or until melted, set aside and cool. In large mixer bowl, stir together flour, sugar, cocoa, baking soda and salt. Add butter, sour cream, eggs, vanilla and melted preserves and beat on medium speed at least 4 or 5 minutes until well blended. Pour batter into the prepared pan. Bake 60 minutes, test at 55 or according to your oven. Cool 15 minutes in pan. Remove and microwave the 1/4 cup of preserves that are left and brush melted preserves over the warm cake. Cool completely. Serve. I serve with whipped cream and chop fresh raspberries in it but if not available, leave plain.