Streuselkuchen (German Crumb Cake) vs Refreshing Key Lime Pie

Both desserts use sugar, butter and egg, but to very different ends. In the Streuselkuchen, egg and softened butter enrich a kneaded yeast dough, while cold butter rubbed into flour and sugar bakes into a thick layer of golden crumbs over the soft, risen base, best served slightly warm or at room temperature. The Key lime pie melts its butter into a lightly salted graham cracker crust and whisks egg yolks with condensed milk and fresh lime juice into a creamy, tangy filling, baked until just set and then chilled. One is bready and crumbly, the other cool, smooth and bright.