Preheat the oven to 350F. Line the bottom of your 10" cast iron skillet/springform pan/baking dish with parchment paper, then grease both pan and parchment paper well.

First, combine the milk and 3 tablespoon of lemon juice in a cup, mix, and set aside for now.

In the bowl of a stand mixer, beat together the softened butter and sugar until light and fluffy.

Beat in the eggs, one at a time, followed by the vanilla extract.

In a small bowl, whisk together the flour, baking powder, and salt.

Add half of the dry ingredient mixture into the beaten butter and sugar, and mix until incorporated.

Stir in the milk + lemon mix, followed by the rest of the dry ingredients.

Pour the cake batter into your prepared pan, then top with the peach slices and blueberries. Drizzle the reserved tablespoon of lemon juice on top.

Now, create the streusel. Melt the butter in a small, microwave-safe bowl, then stir in the flour, oats, cinnamon, and brown sugar until a crumbly dough forms.

Sprinkle the streusel on top of the cake, and scatter the sliced almonds on top.

Bake 40-45 minutes, until golden brown, and a toothpick inserted in the center comes out clean with a few moist crumbs.

Let cool slightly before removing from pan, and enjoy!