Heat oven to 325 Degrees F. Generously coat a 10-cup kugelhopf or bundt pan with nonstick baking spray (such as Baker's Joy), making sure to get into all the ridges.
In medium-size bowl, combine flour, baking powder and salt. Set aside.
In large bowl, beat butter until smooth. Beat in sugar until fluffy. Add eggs one at a time, beating well after each addition. Beat in vanilla. On low, beat in flour mixture, alternating with 1 cup water and the lemon juice. Scrape into prepared pan.
Bake cake at 325 Degrees F. for 1 hour or until toothpick inserted in cake comes out clean. Cool in pan on wire rack for 15 minutes. Carefully trim cake level, run thin knife around cake edge and invert directly onto rack to remove pan. Cool completely.
In medium bowl, blend confectioners' sugar, 2 tablespoons water and lemon extract. Whisk until blended and smooth. Drizzle over cake, allowing to drip down side.
In small bowl, toss together blueberries, raspberries and melted jelly or jam. Fill center of cake with as much of the berry mixture as possible. Serve remaining berries alongside slices of cake.