Preheat oven, grease pan, and prepare apples with flour coating.
Cream butter and sugar, add eggs and sour cream until combined.
Alternate dry ingredients and milk, fold in prepared apples.
Pour half batter, add cinnamon sugar, top with remaining batter.
Use knife to create marble pattern without overmixing.
Cook at 350°F for 55-65 minutes until golden and set.
Rest in pan 10 minutes, then turn out onto wire rack.
Whisk glaze ingredients and drizzle over completely cooled bread.
