Not particularly humid. I would say average. I just made it yesterday, and it was a fairly nice day. I am guessing the crystalization of the powdered sugar has something to do with they process.... ie... Heating the chocolate too much before adding the sugar, or... Heating the chocolate and sugar mixture too much.... or... not heating the chocolate and sugar enough. The "Heat just a little" part of my mom's recipe has always been the most vague to me.

Every since I started making Swiss Meringue Buttercream - it's my go to frosting. Here is a recipe - I think was from Smitten Kitchen. Pure decadence! Makes enough to generously frost 12 regular cupcakes (double the recipe to generously frost and fill a layer cake. Jane Chocolate Swiss Meringue Buttercream 4oz (113g) bittersweet chocolate 6.3oz (around 1.5 sticks, 180g) unsalted butter, room temperature 2 egg whites 3 oz (80g) sugar 1. Melt the chopped chocolate over a water bath or in the microwave. Set aside and let cool. 2. Place egg whites and sugar in a heatproof mixing bowl. 3. Set bowl over 1 inch of water in a saucepan over medium heat. Whisk gently until mixture reaches 140°F/60°C (or until sugar has dissolved and mixture is no longer grainy when you rub it between your fingers) 4. Remove from heat and using an electric mixer, whisk on medium speed until egg whites are cool to touch (this takes a while  should be cooler than your hand). 5. Continue beating, gradually add soft butter by tablespoon pieces and continue to beat. It will first look watery or separated, but after 10-15 minutes, it will come together. 6. Once desired, pipe-able consistency has been reached, fold in cooled chocolate until well incorporated.

I like the world peace cookies. World peace Cookies Excerpted from Baking: From My House to Yours by Dorie Greenspan (Houghton Mifflin, 2006). Copyright 2006 by Dorie Greenspan. Makes about 36 cookies I once said I thought these cookies, the brainchild of the Parisian pastry chef Pierre Hermé, were as important a culinary breakthrough as Toll House cookies, and I've never thought better of the statement. These butter-rich, sandy-textured slice-and-bake cookies are members of the sablé family. But, unlike classic sablés, they are midnight dark there's cocoa in the dough and packed with chunks of hand-chopped bittersweet chocolate. Perhaps most memorably, they're salty. Not just a little salty, but remarkably and sensationally salty. It's the salt Pierre uses fleur de sel, a moist, off-white sea salt that surprises, delights and makes the chocolate flavors in the cookies seem preternaturally profound. When I included these in Paris Sweets, they were called Korova Cookies and they instantly won fans, among them my neighbor Richard Gold, who gave them their new name. Richard is convinced that a daily dose of Pierre's cookies is all that is needed to ensure planetary peace and happiness. * 1 1/4 cups all-purpose flour * 1/3 cup unsweetened cocoa powder * 1/2 teaspoon baking soda * 1 stick plus 3 tablespoons (11 tablespoons) unsalted butter, at room temperature * 2/3 cup (packed) light brown sugar * 1/4 cup sugar * 1/2 teaspoon fleur de sel or 1/4 teaspoon fine sea salt * 1 teaspoon pure vanilla extract * 5 ounces bittersweet chocolate, chopped into chips, or a generous 3/4 cup store-bought mini chocolate chips 1. Sift the flour, cocoa and baking soda together. 2. Working with a stand mixer, preferably fitted with a paddle attachment, or with a hand mixer in a large bowl, beat the butter on medium speed until soft and creamy. Add both sugars, the salt and vanilla extract and beat for 2 minutes more. 3. Turn off the mixer. Pour in the dry ingredients, drape a kitchen towel over the stand mixer to protect yourself and your kitchen from flying flour and pulse the mixer at low speed about 5 times, a second or two each time. Take a peek if there is still a lot of flour on the surface of the dough, pulse a couple of times more; if not, remove the towel. Continuing at low speed, mix for about 30 seconds more, just until the flour disappears into the dough for the best texture, work the dough as little as possible once the flour is added, and don't be concerned if the dough looks a little crumbly. Toss in the chocolate pieces and mix only to incorporate. 4. Turn the dough out onto a work surface, gather it together and divide it in half. Working with one half at a time, shape the dough into logs that are 1 1/2 inches in diameter. Wrap the logs in plastic wrap and refrigerate them for at least 3 hours. (The dough can be refrigerated for up to 3 days or frozen for up to 2 months. If you've frozen the dough, you needn't defrost it before baking just slice the logs into cookies and bake the cookies 1 minute longer.) Getting Ready to Bake: 5. Center a rack in the oven and preheat the oven to 325 degrees F. Line two baking sheets with parchment or silicone mats. 6. Using a sharp thin knife, slice the logs into rounds that are 1/2 inch thick. (The rounds are likely to crack as you're cutting them don't be concerned, just squeeze the bits back onto each cookie.) Arrange the rounds on the baking sheets, leaving about 1 inch between them. 7. Bake the cookies one sheet at a time for 12 minutes they won't look done, nor will they be firm, but that's just the way they should be. Transfer the baking sheet to a cooling rack and let the cookies rest until they are only just warm, at which point you can serve them or let them reach room temperature.

My chocolate cake recipe can be baked in any shape container. I do it as 8" layers, 10" layers, 10" square, loaf, cupcakes and whatever else I have in the cupboard. Do the math to work out how much mixture you'll need. I'm guessing about 1 1/2 times the original recipe going by my own experience.