PreparationFor chocolate sauce: Bring cream to simmer in medium saucepan. Remove from heat. Add chocolate. Whisk until smooth. For streusel: Preheat oven to 350°F. Mix all ingredients in bowl. Rub together with fingertips until small clumps form. Spread on rimmed baking sheet. Bake until golden, stirring occasionally, about 18 minutes. Cool streusel on sheet. For blondies: Preheat oven to 350°F. Butter 8x8x2-inch metal baking pan. Using electric mixer, beat butter and both sugars in bowl to blend. Beat in egg, then vanilla. Sift flour, baking soda, and salt over; beat just until combined. Stir in chocolate chips. Spread batter in pan. Bake until golden around edges and tester inserted into center comes out clean, about 23 minutes. Cool in pan on rack. Cut blondies into 1-inch squares. Arrange 5 squares in bottom of each dish. Rewarm sauce; spoon over. Top with ice cream, more sauce, then streusel.
PreparationFor chocolate sauce: Bring cream to simmer in medium saucepan. Remove from heat. Add chocolate. Whisk until smooth. For streusel: Preheat oven to 350°F. Mix all ingredients in bowl. Rub together with fingertips until small clumps form. Spread on rimmed baking sheet. Bake until golden, stirring occasionally, about 18 minutes. Cool streusel on sheet. For blondies: Preheat oven to 350°F. Butter 8x8x2-inch metal baking pan. Using electric mixer, beat butter and both sugars in bowl to blend. Beat in egg, then vanilla. Sift flour, baking soda, and salt over; beat just until combined. Stir in chocolate chips. Spread batter in pan. Bake until golden around edges and tester inserted into center comes out clean, about 23 minutes. Cool in pan on rack. Cut blondies into 1-inch squares. Arrange 5 squares in bottom of each dish. Rewarm sauce; spoon over. Top with ice cream, more sauce, then streusel.