Preheat oven to 325°F (165°C). Grease and fully line two 7.75 x 3.75-inch loaf pans with parchment.

In a medium bowl, whisk cake flour, cornmeal, cornstarch, baking powder, baking soda, and salt until evenly combined.

In a large bowl, whisk brown sugar, granulated sugar, oil, yogurt, vanilla, non-dairy milk, and vinegar until completely smooth.

Add dry ingredients to wet and whisk just until combined. Batter will be thick and glossy.

Set batter aside while preparing peaches and streusel.

Place frozen peaches in a sieve over a bowl and thaw at room temperature 30-45 minutes.

Gently press to release excess liquid and discard liquid.

Weigh peaches - you should have 220-240 g after draining.

Add drained peaches to a saucepan with sugar, cornstarch, and salt.

Cook over medium heat, stirring constantly, 3-5 minutes, until lightly thickened and glossy.

Remove from heat and cool completely before using.

Combine flour, both sugars, and salt in a bowl.

Stir in melted butter until large damp clumps form with loose crumbs.

Keep at cool room temperature. Do not chill.

Divide batter between pans, filling each pan about one-third full.

Sprinkle a thick, even layer of streusel over the batter. Lightly press to adhere.

Spoon cooled peach mixture evenly over the streusel (½ per loaf).

Add remaining batter, spreading gently to fully cover peaches.

Finish with a very generous streusel layer on top. Do not press.

Bake uncovered for 45 minutes.

Loosely tent with foil and continue baking 10-15 minutes, until done.

Loaves are fully baked when the internal temperature in the cake portion (not fruit or streusel) reaches 200-205°F (93-96°C).

Cool in pans 20 minutes, then remove and cool completely on a rack.

Wisk all glaze ingredients together.

Drizzle over cooled loaves.