Button content is not showing with inner controlTemplate - wpf

Question

I created a grid with two buttons, i created an inner template for the first button; and button template in resources for the second one.
the problem is that i don't understand why the inner template don't show the content of the button ???
<Window x:Class="WpfTest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfTest"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<ControlTemplate x:Key="ButtonTemplate" TargetType="Button">
<Border BorderBrush="Orange" BorderThickness="3" CornerRadius="2" Background="Red" TextBlock.Foreground="White">
<ContentPresenter HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="{TemplateBinding VerticalAlignment}"/>
</Border>
</ControlTemplate>
</Window.Resources>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Button Grid.Column="0" Content="Button_A" >
<Button.Template>
<ControlTemplate >
<Border BorderBrush="Orange" BorderThickness="3" CornerRadius="2" Background="Red" TextBlock.Foreground="White">
<ContentPresenter ContentSource="Content" HorizontalAlignment="{TemplateBinding HorizontalAlignment}" VerticalAlignment="{TemplateBinding VerticalAlignment}"/>
</Border>
</ControlTemplate>
</Button.Template>
</Button>
<Button Grid.Column="1" Content="Button_B" Template="{StaticResource ButtonTemplate}">
</Button>
</Grid>
</Window>