Crumble – 1 2/3 cup (215g) all-purpose flour – 1/4 cup (30g) cornstarch – 1/2 cup (105g) light brown sugar, packed – 1/2 cup (100g) granulated sugar – 1 tsp ground cinnamon – 3/4 cup (180g) salted Kerrygold butter, melted Coffee Cake – 1/4 cup (55g) salted Kerrygold butter, room temp – 3/4 cup (150g) granulated sugar, divided – 2 large eggs, room temp – 1 tbsp vanilla extract – 1 cup (230g) sour cream, room temp – 3/4 tsp baking soda – 1/4 tsp kosher salt – 1 1/2 cups (195g) all-purpose flour – Powdered sugar, for dusting
Crumble Mix flour, cornstarch, brown sugar, sugar, and cinnamon in a medium basin. Add the butter and stir until the crumble is well moistened. It should be clumpy and dense.