Combine flour, 1 tablespoon sugar, baking powder, and salt in a medium mixing bowl; stir well. Beat egg yolks in a small mixing bowl. Add milk, beating well. Stir milk mixture into dry ingredients; add melted butter, stirring just until moistened.
Beat egg whites (at room temperature) until stiff peaks form. Fold into flour mixture. Gently stir in pineapple.
Drop mixture by tablespoonfuls into deep, hot oil (375°). Fry until golden brown, turning once. Drain on paper towels.
Combine 1/4 cup sugar and cinnamon in a small mixing bowl. Roll fritters in sugar mixture. Serve immediately.