Preheat oven to 350°F. Grease a 9-inch* round cake pan and set aside.
Using a stand mixer with the paddle attachment, beat butter and sugar on medium speed for 3-4 minutes, until light and creamy. Add eggs, one at a time, beating to combine. Add vanilla extract, almond extract, and sour cream.
In a separate bowl, combine the 1-1/4 cups flour, baking powder, baking soda, and salt. With the mixer on low speed, slowly add flour mixture to wet ingredients. Beat until just combined. Do not over mix.
In a separate bowl, toss the diced peaches with 1 additional tablespoon of flour.
If you're adding the peaches INTO the cake batter: using a rubber spatula, carefully fold the peaches into the cake batter. Pour the batter into the prepared pan and smooth into an even layer. Crumble the topping over the batter.
If you're adding the peaches ON TOP of the cake batter: pour the batter into the pan, and spread it into an even layer. Spoon the peaches on top of the batter, spreading them into an even layer. Crumble the topping over the peaches.
Bake for approximately 45-55 minutes, until a toothpick inserted into the center comes out clean. Cool on a wire rack. Run a thin knife around the outside of the cake to help remove it from the pan.
Garnish: You can drizzle the cake with icing, dust it with powdered sugar, or serve it with ice cream or whipped cream. To make icing: whisk 1/4 cup powdered sugar with a tiny splash of milk and a drop of vanilla extract. Adjust the consistency by adding more powdered sugar (to thicken) or more milk (to thin).