Maple Raspberry Sour Cream Coffee Cake with Caramel Cheesecake Frosting

It's time we talk about flour.

It's such a common ingredient that it can be easy to look past it.

Flour makes up majority of the ingredients in most bakery recipes. It would make sense that the type and quality makes a difference on your baking.

All-purpose flour is favoured by most of us because it can be used in so many applications. Why keep 3 or 4 different flours taking space in your pantry if one flour can do it all?

I get it. I'm with you.

But... (you knew this was coming) there is a time and place for each one.

In this recipe here, and in most butter cakes or other high fat and higher sugar cakes (like pound cake and coffee cake or yellow butter birthday cakes) that are meant to be moist and dense yet still soft, then Hi-Ratio Cake Flour is extremely helpful. It's called "Hi-Ratio" because it is designed to perform even in recipes that contain a high quantity of sugar and fat relative to flour.

Not only does cake flour have a lower protein content and often a finer texture than all-purpose flour, but it is usually chlorinated or "bleached" which is what gives it special properties, although it doesn't sound so nice to eat bleached flour... I understand. (More on that farther down).

Chlorine has an effect on wheat starch molecules, allowing them to swell and absorb more water more readily so that the structure in the cake sets quickly despite all that fat and sugar than can typically weigh it down. This water absorption means a moist cake and a soft texture. The lower protein content also promotes a tender texture.

This cake, with that whole 1 cup of full fat sour cream and moisture-laden frozen berries, really benefits from using cake flour because, well there's a lot of fat and a lot of liquid! Fat gets in the way of protein cross-linking and starch gelatinizing which is all necessary to set the structure of the crumb. Bleached flour is powerful in that it can still set despite all of these obstacles.

You certainly can use all-purpose flour for this recipe (or a blend of each - my preference!) but such a hefty amount of batter in one pan and a slow bake (about 1 hour) could mean that the center might end up too dense and stodgy and even if it is slightly under-baked it can collapse in the middle. It is not uncommon to have dry edges and gooey middles with these types of cakes. Much of this depends on the accuracy and efficiency of your oven as well, but has a lot to do with how well the flour can handle the amount of moisture, fat and sugar in a recipe.

To overcome that, you could also make this as two smaller 8-inch layers and stack them up. Either way, you will end up with a dense yet soft, moist and totally moreish cake.

How to make cake flour at home?
Another trick that some home bakers use to mimic the effects of bleached cake flour is to substitute 2 tablespoons of corn starch or potato starch for 2 tablespoons of unbleached all-purpose flour for each 1 cup (142g) of total flour in the recipe. This serves to dilute the protein content of the flour component in the recipe and provides additional starch gelatinization. Both of these starches gelatinize (absorb water and set the structure) at a lower temperature than starch in wheat flour. Moreover, potato starch is much more effective than corn starch with its lower gelatinization point.

However, using this trick does not impart the enhanced water-absorption properties of Hi-Ratio flour. To do this, you can heat-treat the flour by placing it in the microwave for 1-2 minutes (depending on how much flour you are using) with frequent stirring. Steps to this method are laid out here.

How 'bout that Cheesecake frosting?

Well, it's called "cheesecake" and not "cream cheese" frosting for a reason. With no icing sugar (and very little added sugar overall) this luscious frosting is rich, dense yet airy and pillowy, and really does taste like creamy luscious cheesecake.

The trick to giving it that slow-baked caramelized taste is by using brown sugar - not icing sugar. Recipes for frosting typically use icing sugar because it is so finely ground that it dissolves easily and readily. With this recipe, which uses twice the amount of cream cheese compared to butter, there is enough moisture in it to dissolve the rather large granules of brown sugar. Cream cheese is about 35% fat, which means it is about 60% water.

And the best bit - the dulce de leche! It gives it a milky, caramelized and almost savoury flavour that mimics the taste of baked cheesecake and also lends a denseness and smoothness that makes it irresistible. You can also use cold thick butter caramel. The one from this recipe is a dream.

I normally recommend serving buttercakes at room temperature, but a slice of this cake straight from the fridge, with that caramelly cheesecake frosting set nice and thick is nothing short of pure pleasure.

Maple Raspberry Sour Cream Coffee Cake with Caramel Cheesecake FrostingMakes one large 9-inch round cake or two 8-inch layers
For the cake:7 tablespoon (100g) soft unsalted butter1 cup (200g) granulated sugar¼ cup (60ml) maple syrup1 teaspoon pure vanilla extract2 large eggs1 ⅔ cups (215g) Cake Flour or homemade cake flour (see above)½ teaspoon baking soda1 teaspoon baking powder¼ teaspoon salt1 cup (237ml) full fat sour cream1 cup (4oz/113g) fresh or frozen raspberries
For the frosting:¼ cup (56g) unsalted butter4 tablespoon (60g) packed dark brown sugar4 oz (113g) cream cheese3 tablespoon (45ml) Dulce de Leche or thick caramel½ teaspoon vanilla extract1 tablespoon (15ml) 10% cream
Preheat your oven to 325 degrees F. Butter and flour the sides of a 9-inch round springform pan and line the base with a round of parchment paper.
In the bowl of a stand mixer fitted with the whisk attachment, beat butter and sugar until smooth and slightly pale, about 2 minutes. Scrape down the sides and bottom of the bowl a few times while beating. Mix in maple syrup and vanilla. Beat in eggs one at a time until the mixture is smooth and fluffy.
In a separate bowl sift together flour, baking powder, baking soda and salt. Add to the butter mixture alternating with sour cream in 3 parts, mixing on low between additions. Once all added, mix on medium-high until batter is smooth and creamy. Fold in berries then spread into prepared pan. Bake for 50-55 minutes until a skewer inserted into the center comes out clean.
To make the frosting, beat butter with brown sugar until light and fluffy. Beat in cream cheese a little at a time until very smooth. Add dulce de leche and vanilla and beat until creamy. Drizzle in cream to loosen mixture and beat until very smooth and fluffy. Dollop over cooled cake and spread it out to the edges. It is ready to serve!