Kefir pound cake

Ingredients:

• 340 g unsalted butter, cut into pieces and softened, plus 1 tbsp.
• 450 gr. confectionery flour, plus 2 tbsp.
• 450 g of sugar
• 4 large eggs at room temperature
• 1 tsp vanilla extract
• 1/2 tsp coarse salt
• 1 cup kefir or buttermilk at room temperature

Preparation:

1. Place a rack in the middle of the oven and preheat to 190C.
2. Grease a 25cm (10in) aluminium loaf pan or two 23cm x 13cm (9x5in) loaf pans with 1 tbsp (15g) butter and dust with 2 tbsp flour.
3. Combine the remaining 340g butter and sugar in the bowl of a stand mixer and beat for 6 minutes on medium speed using the paddle attachment. Stop the mixer once and scrape the batter from the sides of the bowl with a spatula. With the mixer on the lowest speed, beat in the eggs one at a time, making sure the previous egg is completely incorporated before adding the next one. Stop the mixer again and scrape the batter from the sides of the bowl. This will take about 1.5 minutes. Add the vanilla extract and salt and beat on medium speed for 30 seconds.
4. Set the mixer to the lowest speed and add the flour in three additions, alternating with the kefir: start with the flour and end with the flour. Make sure the previous addition is completely combined before adding the next addition. After adding the last addition, beat the dough for another 30 seconds at medium speed until almost smooth.
5. Pour the batter into the prepared pans, and if using two pans, try to divide the batter evenly. Bake for 1 hour in a springform pan or loaf pan, until the internal temperature reaches 100°C (212°F) on a candy thermometer. The surface of the cake should be golden brown and spring back when pressed, but the crack in the center should still be moist.
6. Remove the cake from the oven and place it on a wire rack for 10 minutes. Remove the cake from the pan(s) and cool on the rack for another 10 minutes. Store the cake on a wire rack, covered with a kitchen towel, for up to three days.